I’s quite common unfortunately. See:
AMD also has processors without integrated graphics, I believe the Ryzen 8000 F-series is an example, as well as older non-G-series processors.
I disagree but that’s a side-topic.
AMD’s “full fat” graphics drivers are built into the kernel already, so disabling them would make little sense and would be difficult (similar to disabling Intel’s graphics drivers). Those drivers are also used for AMD’s iGPUs so they’re needed in any event.
We need some way for NVIDIA users to get graphics output though even if we disable Nouveau by default, since like discussed above integrated graphics are oftentimes just not there.