I have two AMD Radeon cards for Linux that I’m pretty happy with that replaced a couple of Nvidia cards. They are an RX6800 and an RX6700XT. They were both ex mining cards that I bought when the miners were dumping their ethereum rigs, so they were pretty cheap.
If I had to buy a new card to fill that gap, I’d probably get a 7800XT, but if you don’t game on them you could get a much lower end model like an RX7600.