So does AMD.
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/lin...
And while they have an open version of the userland, it's also missing features compared to the proprietary one, etc.
Besides, in the end it truly hardly matters whether the firmware is loaded at runtime or lives in updateable flash. It's still not "your PC" in the Stallman sense either way, it's been tivoized regardless of whether firmware is injected at runtime or during assembly.
Firmware is also the only way to get proper HDMI support... which is why AMD still does not support HDMI 2.1 on linux. HDMI Forum will not license the spec openly and implementations must contain blobs or omit those features.
Can we really assign blame to them specifically for not fighting the hdmi forum on our behalf?
That said, I think AMD isn't really competing with Nvidia. Sure, their R&D budget is smallish but it feels like they're somewhat fine with the current status quo.