When I upgraded my GPU last I tried for the first time since ATI was a thing to leave nvidia and go AMD. I tried to get a 6900XT but just had endless issues with drivers, which I was surprised about because if you believe a majority of Linux users it should have been flawless - it was not. I had endless issues with drivers and games running badly. I caved and returned it for a 3070ti - trust me I tried a lot of things.
Anyway, I've since tried AMD again and upgraded to a 9070XT and the transition this time has been absolutely flawless, even keeping the same install (CachyOS has a guide to swap from nvidia to AMD).
This is all to say, don't believe the hype around AMD but at least give it a try and don't feel too bad if it doesn't work out for you. Ultimately both nvidia and AMD have been improving significantly over the years
No, but you'll need to descale it pretty regularly if you have hard water. They start off looking nice, but end up looking trash after a while.