i'm a little thrown, because the Wayland diagram doesn't feel quite right. the compositor does lie between the kernel and the apps, but IIRC the apps have their own graphics buffers from the kernel that they are drawing into directly. the compositor then composites them together. to me, that feels more like the kernel is at the center of the diagram here: the wayland compositor is between the kernel and the output / input.

i don't think it has a huge impact on the discussion here. but this is such a key difference versus X, that i think is hugely under-told: Wayland compositors all rely on lots of kernel facilities to do the job, where-as X is basically it's own kernel, has origins where it effectively was the device driver for the gpu, talking to it over pci, and doing just about everything. when people contrast wayland versus X as wayland compositors needing to do so much, i can't help but chuckle, because it feels like the kernel does >50% of what X used to have to do itself; it's a much simpler world, using the kernel's built-in abstractions, rather than being multiple stacked layers of abstractions (kernels + X's own).

it means that the task of writing the display-server / compositor is much much much simpler. it's still hard! but the kernel is helping so much. there's an assumed base of having working GPU drivers!

author appears to super know their stuff. alas the FOSDEM video they link to is not loading for me. :(

one major question, since this is a protocol, how viable is it to decompose the window management tasks? rather than have a monolithic window manager, does this facilitate multiple different programs working together to run a desktop? not entirely sure the use case, but a more pluggable desktop would be interesting!