Since there are many wayland compositors, wayland clients must be very conservative (don't be fancy) and most of all respect the dynamic discovery of the interfaces and features and must adjust (from core to stable interfaces).

For instance, a compositor may not support a clipboard, and the "data" related interfaces must be queried for availability (those interface are stable in core) and the client must disable such functionality if not there (for instance, wterm terminal is faulty because it forces a compositor to have such interfaces... but havoc terminal is doing it right). I don't know yet if libSDL3 wayland support "behaves" properly. wterm fix is boring but should be easy.

As wayland usage, it is probably almost everwhere (and Xwayland is there for some level of legacy compatibility).

(I am currently writting my own compositor for AMD GPUs... in risc-v assembly running on x86_64 via an interpreter)