The irony of the Raspberry Pi in particular is that while the ARM side has seen multiple order of magnitude jumps in performance, the GPU and compositor hardwar

The irony of the Raspberry Pi in particular is that while the ARM side has seen multiple order of magnitude jumps in performance, the GPU and compositor hardware have of course remained at its original 2009 atrocious level. The result is that the CPU drawing on a screen-sized framebuffer is fast enough that Raspbian will probably never, ever make the jump to full bells-and-whistles mainline VC4 drawing and atomic DRM composition. It would just end up using a lot more memory and break a bunch of hacks in the proprietary drivers that people have come to rely on for essentially still garbage tier performance and a system that randomly freezes because you ran out of graphics memory (which is forever limited to 256 MiB, memory that you surrender on boot to the horrendous CMA system). I like the Pi a lot as a PoC platform given the availability and the fully open-source supported driver we have for it. But the HW specifications of all the parts that Wayland cares about make it very clear that the thing was only ever meant to do 1080P when you are piping frames from the video decode engine straight to the compositor and out the pixel valves.