Honestly Proton is catching up a lot and the compatibility is impressive but I've had my fair share of problems with it, e.g. on Ice Lake graphics it performed really badly for some simple games without running experimental branches, input was laggy on a few games, simply busted rendering, etc. This can be fixed with time, patches, experimental branches and bug reports, but if you want to play the latest stuff it's all a bit of a chore to some extent. So, more or less, the usual complaints you read about Linux and have been reading about for years, if you're a Linux fan. I think a lot of the old adage "post your specs" applies here; drivers and graphics cards alone will have a massive impact on compatibility, so it's hard to "guestimate" how valid some reports or issues really are without trying the game.
For some older titles though I've been relatively impressed by Proton and e.g. CrossOver. Like Shadow of the Tomb Raider or Witcher 3. You can't play simple 2D games released this year but a 5 year old AAA game can run mostly OK, stuff like that.
There is also a flip side to the billion knobs thing which is that Linux might actually be a reasonable route to run some older games in the future, e.g. games like Deus Ex HR had some fun mods but some of them eventually became incompatible with newer Windows versions. It's not a guarantee (some of these games/mods do insane things) but for some classes of games, things like patched proton/wine builds may be a valid way to preserve them more easily into the future.
For some older titles though I've been relatively impressed by Proton and e.g. CrossOver. Like Shadow of the Tomb Raider or Witcher 3. You can't play simple 2D games released this year but a 5 year old AAA game can run mostly OK, stuff like that.
There is also a flip side to the billion knobs thing which is that Linux might actually be a reasonable route to run some older games in the future, e.g. games like Deus Ex HR had some fun mods but some of them eventually became incompatible with newer Windows versions. It's not a guarantee (some of these games/mods do insane things) but for some classes of games, things like patched proton/wine builds may be a valid way to preserve them more easily into the future.