Playing fast FPS games under wayland/xwayland (and under Gnome/gnome-shell/mutter) is currently suboptimal. It's because gnome-shell will pass mouse moves only at the speed of your monitor refresh rate (see https://blogs.gnome.org/shell-dev/2021/12/08/an-eventful-ins... for the explanation)

I have a 240Hz monitor, so gnome-shell passes data to xwayland and then to applications at ~220Hz (as seen in the event-freq from https://blogs.gnome.org/shell-dev/2021/12/08/an-eventful-ins...)

So, my expensivish 1kHz (or even 8kHz mice - as these exist) will pass mouse movements with 4ms+ delay and only <240 times per second.

Under Xorg, the xinput proto will pass data at the ~usb polling speed. For my 2kHz mouse, the tool (event-freq) shows ~1700 events / second.

By the way, this ~220Hz is the speed at which gnome-shell passes data to clients (via XWayland or directly). The libinput accepts and passes data at correct 2kHz - and it's only gnome-shell aggregates it under wayland - this can be seen e.g. in the evhz tool (direct /dev/input access) vs event-freq tool (gnome-shell in wayland session, and xinput in xorg session).