Edit: factorio and oxygen not included have both been pretty solid, too. I think factorio is even native.
But what you're writing is basically what Linux gamers were writing for many years - even before Valve started focusing on it too.
That's the one bad experience I had with the game - in Steam it is already marked as available on Mac OS but after downloading the 100GB it tells you that it's actually still the Early Access version (with incompatible save files!) and you have to wait till September for the actual game. Which meant another 110GB download on my fallback device.
That Apple made GPT but then ignores this obvious route, instead thinking it will somehow mobilize game developers to port their games natively to their bespoke low-level graphics API - you see, they just didn't know about the graphics capabilities of Apple Silicon before!
Lots of game developers can barely be convinced to release usable Windows binaries, see also the mess of badly performing DX12 games (where you have to treat your windows target more like a low-level console API that needs optimization that just isn't there) vs yeet the pixels out DX11.
No. Linux gaming thrives because Valve embedded Wine directly, branded as Proton, into the Steam launcher. GPT is the same, only for the Mac target of wine rather than Linux, and obviously Apple can't integrate it into Steam.
In terms of compatibility I've been using Whisky (a wine UI wrapper) + GPT for a few weeks now and window steam loads fine (albeit slowly), and all the windows games I play work fine (certainly far better than wine - GPT).
Of course the problem here is that it's not cleanly integrated into native Steam, so it's (1) requires a separate launcher installed, (2) requires a separate steam install, and (3) if the game ever does get ported you'd need to migrate your saves from the windows container wine uses.
This ignores all the attendant performance thrown away by shader translation (that linux also suffers) and cpu translation (that any non-intel code suffers, but in practice that's just Mac)
I've seen better-behaved Mac GTK apps.
It appears that there is some problem with BG3 on GFN. The game’s launcher constantly complains about “corrupt data files” and cloud saves take some time to sync from and to Steam.
I was hoping for that trend to reverse with game porting toolkit, but it doesn't seem like that's happening. Whoever pushes for Gaming at Apple doesn't seem to have massive internal support. Metal VR died almost as soon as it released and somehow they thought making Game Porting Toolkit license incompatible with Wine/Proton/CrossOver was a great move, because all you need to convince a game developer to invest in a dead (to your audience) platform that will likely deprecate your API in a year or two is a proof of concept of how well it can run.