I can’t think of any hardware that Valve has abandoned. Sure they’ve stopped making plenty, but pretty much everything is still supported, and in many cases works even better because the software developed for them still exists and gets updated(SteamVR, Steam Input, Steam Link, etc). Closest you can get to abandonment were the Steam Machines, and even then they were just PCs and you could easily install another Linux Distro on them, or even Windows.