That was true, we need to research and see if it's still true. Gnome have dropped their cap_sys_nice.
For setting nice we many options: - kwin_wayland_wrapper can be cap_sys_nice set it the nice a child PID (needs verifying) - maybe the systemd cgroup settings for priority are as good/better - rtkit EGL contexts Carlos from Mutter says in a related gnome MR: "EGL_CONTEXT_PRIORITY_HIGH_IMG is already obtainable without additional capabilities (at least in the i915 driver)" https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2284 There's also an open mesa MR to cache context prioirty perimissions at the time the context is created, which might allow for dropping after initial setup.