I guess it is just about there being various different alternatives for the same thing, and different distros (or even different versions of the same distro) deciding to use one over another, for reasons unknown. For instance, in the NTP example where Ubuntu 18.04 uses timesyncd instead of ntpd by default, I could have disabled timesyncd and installed+enabled ntpd (or chrony or whatever...) instead if I really wanted, but since timesyncd was already there running doing its stuff, I decided to keep using it there.

Normally I wouldn't mind but at my current job I need to support several different clients who use different distros or versions of distros. So for now I don't necessarily try to depend on my memory on how to do even some of the most simplest admin things, but first google for it (e.g. "ubuntu 18.04 static ip") just to double-check how it is performed on that specific linux distro version. Luckily it is quite easy to find that info online, at least for RHEL and Debian derivatives.

Linux machines could keep running for years.
Windows machines need rebooting repeatedly.

Some specific Linux distros are not very stable, but my Linux machines often have uptime up to one year.

I would say that's dependent on what you want it to do / what you want out of your system;

Choose Gentoo if you want speed and want to learn/grow. Perhaps end up on Linux From Scratch later...

Choose Sabayon or Mint if you're the casual user that wants some stability, best hardware support and just the most "out of the box"-experience.

Choose Debian derivatives if you want least hassle / better support towards gaming, such as Ubuntu, SuperGamer or Mint.

Choose an older original distribution like Debian or Gentoo if you want a stable, solid, all-purpose server. Forget "bleeding-edge" software here. (Although, I hear Arch and Slackware is also stable, but these I've not tried in almost 20 years). Would recommend Red Hat here in the past but Red Hat and it's derivatives just lost it for me a long time ago, mainly due to hardware troubles.

Choose IncludeOS if you want to host servers/apps with the least overhead in the sky.

Choose QubesOS, Pentoo, Parrot, Kali, or Tails if security/privacy/pentesting/forensics is you main concern.

Choose ReactOS, PuppyLinux or TinyCore if you want support for older hardware or an OS that is really small.

For multimedia (audio/video) production: No matter the distro, choosing a kernel with relatively low latency for multimedia is crucial. Choose others for firewall.... I mean, the list is endless - but my personal mains are Mint and Sabayon.

I just abhor Windows and I've done that ever since Windows Vista came out. MS / the OS NEVER respects you as a user and treats you as a dumb goose (well, macOS is actually worse there), doesn’t allow you to change what you want, changes things and spys on you behind your back, horrible security and stability (let's face it, every software has bugs and problems... and some more than others), and you can't see the source. And yes, constant reboots. If I wasn't a gamer I would've ditched Windows a long time ago.

This is the Linux Distribution Timeline map, from ca 1992 to 2018:
https://i.imgur.com/VgRID3s.png (about 5MB)

PS: Not directly based on Linux, but if someone wants to experience an os that was first/best/fastest on multithread/cores back in the early 90's, check out BeOS/HaikuOS: https://www.haiku-os.org/

I have a copy of official BeOS install CD floating around somewhere just because BeOS had the promise of doing so so much.

It's not just that there are alternatives.. it seems the Linux community is in general not very willing to commit to a solution and keep it and just improve it. Instead, they have alternatives, they make *more* alternatives, and they switch between them when the previous alternative is no longer fashionable or lacks some functionality or has some bugs and nobody wants to fix it. It just leads to churn and change in general.

Systems like OpenBSD are quite different in this respect since they are a complete OS with all the parts included, rather than a distro composed by taking a kernel and throwing a collection of third party alternatives (plus customization) at it. So on OpenBSD there's usually (only) one tool and they have incentive to keep it good and fresh and maintained instead of chasing alternatives and switching suppliers when it seems convenient. And because these tools are developed in unison with the rest of the system, they integrate well. Sometimes they rewrite tools or parts of them but that doesn't mean the UX completely changes; unless there's a damn good reason to change it, they purposefully *avoid* changing it. Compare to the situation in Linux land, where if people decide to switch over to another implementation of some protocol/tool, it's likely to have different UX. It was written by different people, in a different context, with different goals, as a different project.

Maybe things are settling down a little in the Linux land as big projects like systemd become the hard default everywhere and gain enough critical mass that nobody's going to seriously try replace them. Go and tell. The irony is that systemd caused so much churn, far more than any single project in the past. On the other hand, I'm not quite convinced that things will settle because there are enough people who are perpetually pissed off at systemd (me included, I guess). It's just not something everyone wants to settle on. And on the other hand its scope is so large that I'm concerned that alone creates incentive for some genius to do it better and replace the whole thing like they're reinventing web frameworks left and right. (Contrast with tiny tiny tools that just do their simple job in 1000 lines of code written in the 80s.. these seldom need repeated revolutionary replacements)

I tested Zorin OS some time ago and found it good for me as I use mainly Windows 7 and like it a lot.
It was Zorin 9 LTS and for anyone coming from Win 7 it was like a small change.

Problem was that my printer.scanner had no driver so I sticked to Win 7.

Now I ask the Linux experts among you : I see Zorin 12 is now available, probably looking more like Win 10 now. Is it worth giving it a try ?
Zorin 9 was already not the "lightest" of Linux distribution, asking a lot from CPU (more than Win 7). Was that part optimized with Zorin 12 ?

Thanks in advance for your answers.

To be honest, Zorin is just a kitted up Ubuntu with a bunch of theming already applied. As for the lack of printer/scanner driver, I somehow doubt that. Unix and Printing Standards go hand in hand. Could the devs of Zorin really not included the SANE backend or a version of SimpleScan?
What about Fedora, Arch, Manjaro, Mageia, SuSe?

Clarry, please. As a fellow Unix user, do you really think I want to build my own init script and call upon the modules myself, whose names I do not even know of?

Think of it this way. As a wizard, I could record the runes to memorize my daily spells, or I could just invoke a scroll to have that automated so I don't have to spend an hour in the morning just to inscribe some coffee.

I know it is Unbutu with Windows-like look, but that's exactly what I liked : the Win 7 look alike. ;-)
Printer is a Lewmark x2670, I could print in black but was unable to scan anything nor print in colour. I asked on Linux forums, tested some drivers the members suggested, all with same limitation.

Yes, but it's entirely unnecessary, except as training wheels. Once you go beyond the limitations of what the Microsoft design philosophy contained you in, you'll find an entirely new world of workflow awaiting you, especially if you dive into the various DEs and WMs.

You're putting words in my mouth, and then you're making a straw man by pretending that systemd is the only way to automate anything and the only alternative is writing your own scripts to every problem. I'm not even going to engage, because that is too fucking stupid.

Ubuntu

I really like Debian for server and day-to-day work.
Debian is the biggest, most widely used distro with a huge community behind it. It supports most architectures and features thousands of packages.
Moreover, Debian is the distro closest to the spirit of Linux.
Debian has several flavours like stable, testing and unstable. So, if you want stable packages, get stable. If you want new stuff, try testing. Actually, Debian testing flawlessly runs on my Pi 3 (I need the newer kernels for native Debian ARM64 support).
Oh, and Debian does well on Phoronix benchmarks.

- Years ago, when I used Ubuntu, it was quite buggy. Nowadays, it even spies on its users (search function) and due to its strange decisions is often called the Apple of the Linux world.
- Linux Mint is good for beginners, but it relies on Ubuntu which is a bastard of Debian. Thanks to them, we now have the desktop environment Cinnamon which is a big step up from Gnome 3.
- Red Hat is a big corporation sitting in the USA which was recently bought by IBM. I don't trust them -> patriot act. Apparently, they have good support and are therefore favored by businesses.
- Arch/Manjaro have no appeal to me as they are tiny and not as stable as Debian, but they do have a nice Wiki in case you're looking for help with nftables or iptables.

Not sure how stability is measured. Anecdotally, Debian was rather unstable and buggy until in quit using it in a fit of rage. I tried to give it another chance a few years later, ran into issues, got some hand holding from a Debian developer I know.. in the end we both agreed I'm better off using something else. (At that point we'd installed a bunch of backports, a custom kernel, etcetra, and still ran into issues, when everything just worked OOTB on Arch).

IME Arch is more stable than Ubuntu, Fedora, or Debian, though still far from perfect. I can't say I like rolling releases much, but Arch does pull it off well enough. That is to say, I'm always kinda scared and irritated when I need some new or updated package, run a sync, and notice there's a crapton of stuff waiting to be updated. So far it's only crapped itself a few times only, and in rather minor ways.

See, this is my use case for not using Arch. There's about a two week waiting period from Fedora upstream (which i s not too related to RHEL these days) and updates rarely update past the handful when they occur, should you stay with them. (It's a command that can be recalled nearly instantly, no excuse for not running it at least once daily/checking DNFdragora daily.)

Sure, you have to enable RPMfusion, but that's so simple that I feel anyone who is competent enough to follow written instructions could do it.