Hi,
I believe the Raspberry Pi only supports acceleration for OpenGL ES, not for the full/legacy OpenGL specification. Converting KiCad to use GLES should be mostly mechanical, IIRC we don’t really require anything from the non-ES parts of the specification, but it would have to be done before we can expect it to be usable.
Fallback (CPU rendered) graphics will still work, but these use a lot of CPU time and are rather slow.
(This project is in the “I have registered the domain but not yet started on any code” stage of my ToDo list, at current rate I will get to it shortly after GL has been replaced by Vulkan)