I really only have experience with Nvidia cards, and I've been gaming on 4k monitors for about 4 years now. The lowest card I was able to run a 4k monitor with consistent FPS was a GTX 1080ti, and even then, I couldn't max all the graphics settings, with the exception of some very old games. Most 4k monitors are capped @ 60hz, although I've seen newer models recently that go to 144hz, but they're pretty pricey. GTX 2080ti's do really well @ 4k, and I ran one of those for a couple years, but they don't even make them anymore. I was fortunate enough to get a RTX 3080 a couple months ago, and that is awesome for 4k, I can go max settings on most games, though I haven't played CP2077 yet.
That's just my experience with 4k gaming, maybe it can give you some reference points when comparing other cards.