What's the plan for when AMD inevitably drops driver support for them at the worst possible time? I know Polaris has to be next on the chopping block, but they dropped support for the R9 2/3xx range during the last GPU shortage. I'm honestly shocked they still support Polaris, even, and that nVidia still supports Pascal in turn.
I've been able to find volunteer led efforts to get drivers for "unsupported" GPUs years after official support ended. This is most often an annoyance for old notebooks where support vanishes at the drop of a hat about 40 seconds after the last system using that hardware goes out of warranty, but it's not usually a huge issue to dig them up. I was able to find working drivers for a GTX 980 for a ~2012 Mac Pro
last year, although that was more of a "because we can" than anything anyone needed to do.
Beyond that, if somebody is really dead set on gaming and newer cheap hardware truly isn't an option, they can install Bazzite or Mint or whatever and Steam to their heart's content. The GTX 1080 (Ti) is another good option but they're a lot harder to get, need more power and usually cost more like $150 - $175 than sub-$100.
The A770 is technically still faster and they're actually easier to find. My local Microcenter had a few out on the shelves last time I was there. I've never seen a B580 and I've been trying to get one since December of last year. I also saw a 12GB RTX 5070. One, at least. I'm not paying $700 for a 12GB card though.
Yes, Intel Arc cards are spectacularly unpopular, but the "nVidia at all costs" attitude is keeping a lot of people from being able to, you know, actually play games on their computers.