Even though the newest nvidia drivers have started to support GBM, the Wayland compatibility story is still not great. In my experience on Wayland, several OpenGL programs refuse to work, and Vulkan does not work at all. This is with driver 545.
amd uses the gbm properly, nvidia is half cooked and previously used eglstreams instead of because they did not like gbm. reality is every compositor just uses gbm.
So I guess the situation is not simply black & white but a bit more nuanced.