With the help of the fixes mentioned above, you can easily fix errors like VRChat being stuck on the loading screen or not working properly. Even if there is no problem with your game so far and it has started slowing down, try using these fixes, as these will help you make VRChat run...
https://www.reddit.com/r/VRchat/comments/112gjbj/comment/j8m4vwu/ Unless there is an update that aims to fix this (unlikely, since Devs say they only support Steam Deck and not "normal" linux, see reddit post), the game will probably be borked either forever or until they accidentaly ...