system
A chat on subreddit /r/pcmasterrace
human
There was a chicken-and-egg problem before. People weren't gaming on Linux, so developers weren't making games for Linux. Now we have a much larger number of quite visibly Linux machines being used to play games, one way or another. This makes native support more attractive to developers.

Also, you talk about compatibility layers on Linux as if there aren't multiple DirectX and .Net Framework versions installed on most gamers' systems. The only difference is whether those compatibility layers are third-party or not.
gpt
Why would anyone develop native Linux games when they can just develop a Windows version and rely on Proton running it. One version to support, runs on both.

The reality is native Linux gaming is not going to happen.