On PC: It should be reasonable... no clear limit. Obviously, if a game got mediocre content and totally average graphic... 100+ GB is not reasonable.
On Smartphone: Up to 30 GB is OK. Above 30 is slowly going over the edge, as it gets hard to handle it with the big updates and shader compilation after every update.
Actually only got 4 of the most demanding Android games°° there, mainly for testing purpose, and they all are between 20 and 35 GB. I think 20 is enough for great graphics there but up to 30 is fine.
°°Genshin Impact, Honkai Star Rail, Tower of Fantasy and Wuthering Waves
However: Smartphone processors are still doing bigger advancement than PC processors. The newest Snapdragon 8 Elite which is just 1 year more recent already got nearly twice the processing performance vs. the just 1 year older Snapdragon 8 Gen 2 (which is just 1 Smartphone generation for Xiaomi... 14 to 15). A PC can not make such big "steps" and if so... the price will increase drastically (4090 and 5090 is a cash destroyer). On the X86 CPUs not any bigger of a improvement but perhaps Zen 6 might be a bigger step. As well thanks to a smaller node (which is currently Smartphone only).
Not that i enjoy "phone gaming" at all but... they finally are almost hitting PS4 Pro performance (between PS4 and PS4 Pro), with RT, which means... in theory they can already play almost any game and every single GOG classics (if the Windows emulator is not giving up).
AMD is changing the node to something smaller because the server market is asking for... higher efficiency, very critical there. The consumers are not the most important customers anymore... they pay to less and consume to much, i assume.
Of course, "Wuthering Waves", probably the best looking Android game so far (as well those other games) and can be played as a PC version as well... with solid graphics, the specs, which makes it even more clear what a modern "phone processor" is already capable to handle:
Minimum:
Requires a 64-bit processor and operating system
OS: Windows10 64-bit
Processor: Intel Core i5 (9th Gen) / Ryzen 2700
Memory: 16 GB RAM
Graphics: NVIDIA GeForce GTX 1060/AMD Radeon RX 570/Intel ARC A380
Network: Broadband Internet connection
Storage: 60 GB available space
Sound Card: Windows Compatible Audio Device
Additional Notes: HDD Supported, SSD Recommended.
Recommended:
Requires a 64-bit processor and operating system
OS: Windows10 64-bit
Processor: Intel Core i7 (9th Gen) / Ryzen 3700
Memory: 16 GB RAM
Graphics: NVIDIA GeForce RTX 2060/AMD Radeon RX 5700XT/intel ARC A750
Network: Broadband Internet connection
Storage: 60 GB available space
Sound Card: Windows Compatible Audio Device
Additional Notes: SSD Required.
This is a phone game! Some... i mean many... people are moaning that Croc is to demanding.
Sure i can probably emulate Croc on my phone... but i would need the game first.
Currently pretty much "state of art" on phones, yet not the maximum possible because the industry can barely catch up.
Tower of Fantasy VS Wuthering Waves - Details and Physics Comparison:
https://www.youtube.com/watch?v=Rpd4Mf3SCcs