AMD

They are diverting RX 580 into specialized driver support, which will allow them to spend more time on fixing driver issues for more modern cards and adding new features for more modern cards instead of having to make sure its compatible with 400/500 series and then troubleshoot it & make the code work with the 400/500 series, and vice versa (400/500 series bugs/features not meddling with the newer cards' drivers). They aren't getting new features anymore but they are still getting modern game support and security fixes. AMD isn't dropping support, but the card won't be getting new features.