So many games work on Proton/Wine these days, it's not really surprising anymore.

Nowadays you have a huge chunk of games being built on massively popular engines like Unity and Unreal, making it much easier to support/optimise for.

Another big point is that you're not developing exclusively against DirectX. Vulkan is very popular, and both APIs are frequently supported by game engines. This introduces some "good habits", in that it forces the devs to think about compatibility from the get go, instead of trying to come up with shady tricks to get one or two extra fps that only work in specific conditions and crash the game otherwise.