I see you all over this thread and I want to share something you might find interesting.
You keep mentioning the server can't handle the anti cheat because it needs to trust client data. Here's an interesting thought: how is client anti cheat supposed to work when it needs to trust input data?
Look up direct memory access cheats. TL;DR Two computers are hooked up such that PC 1 runs the game, PC 2 reads memory from PC 1, and can then output keyboard/mouse inputs, as well as wallhacks/esp. How is the client side anti cheat supposed to know that the keyboard and mouse inputs are legitimate? How is the client side anti cheat to know wallhacks are being used when they are being rendered on an entirely different machine?
Reasons are usually just newest kernel/mesa/etc. Most of the time the difference is very small, and often inconsequential. However, every now and again there is a major development that might make it worth it (IE: The graphics pipeline that all but made dxvk-async obsolete)