[jillesvangurp]

All the smart ones probably already test their games on proton. IMHO they'd be idiots if they didn't. Stuff just works mostly and when it doesn't it's probably relatively easy to address the issues for developers. And of course the Steam Deck is becoming a pretty popular console so there's that as well. Steam on Linux is becoming a pretty nice juicy market with quite a few users. Targeting that is going to be an easy choice. Especially when it is essentially almost no effort to do so.

[asylteltine]

Most AAA games do not work on proton because the devs refuse to allow the anti cheat to run. Most anti cheat support Linux but the devs have to allow it.

Destiny, R6, cod, etc refuse to support Linux.