Just read an article about a function of the Linux kernel added in 5.19 that nerfs the performance of any app caught causing something called a split lock. I get the gist - doing this affects the performance of the entire system, so there's... Incentive to create a disincentive.
Naturally, this has had an effect on some games running through Proton.
It seems like an absolute head-ass decision to make at a time when non-free binary blob games are driving explosive growth for the linux desktop.
I'm no more than a dabbling coder and I'm sure balancing the needs of server and desktop can be difficult at times, but mannnn, try to read the room.