Extremely limited support for one. Why is it locked behind the 6000 series cards? The project has been around since the 500 series cards days and they utterly ignored the entire market for years.
What exactly is locked to 6000 series cards? I can't speak specifically to having had any old 500 series, but I was using even more ancient 400 series cards (rx480 from 2016) with ROCm for years up until recently. So I am not sure what what issue you would have with 500 series other than probably being old slow hardware, but I don't see why they wouldn't work otherwise¹.
AMD doesn't support any recent consumer GPUs, and they have long-standing support issues failing to build which are sometimes only resolved a year or more after launch.
While AMD might not have "official" support for their consumer hardware lineup on offerings that have traditionally been a non-consumer area of GPGPU, there is plenty of evidence that it will indeed still work just fine on most of them (once compiled properly and sometimes with the right environment flags); as witnessed by me and even people in the link you reference. I agree that "official" support would be great eventually, but for me as long as it works, that's adequate enough for me on consumer hardware.
I think the thread I linked shows there is substantial frustration here, and the reason I didn't purchase a Navi card was in part due to widespread reports that ROCm was untenable on the platform.
> once compiled properly and sometimes with the right environment flags
Not interested in apologism for the corporation. If AMD wants to compete with CUDA, they have to support the consumer GPUs that are accessible to hobbyists and non-experts. This is user hostile support.
¹ https://community.amd.com/t5/knowledge-base/amd-rocm-hardwar...