You said: (Linux) "unusable for any kind of gamedev...".
That's nonsense.
You raise valid points, but they do not support your conclusion that: (Linux) "unusable for ANY kind of gamedev...".
You know that, though. You were hyperbolic, I know that, too.
By the way, you should try Godot. You'll be surprised.
Apparently latest Arc iGPUs are quite competitive.
https://www.tomshardware.com/pc-components/gpus/intel-shows-first-integrated-arc-gpu-benchmarks-for-meteor-lake-up-to-twice-the-graphics-performance-compared-to-i7-1370p