I think the 7800XT will only be 25-30% faster than a 3080 if it's a 60 CU card as the leaks suggest, a bit better than the 4080 12gb but not sure it'll be enough to upgrade from a 3080 especially if it comes in above £650.
A 50% upgrade at the same price is really what I'd be looking for which I think the 7900XT would have delivered but at almost 50% more cost I'm not sure it's worth it especially as RT is not really going to be much better.
maybe in 2 years will hold on to the 3080 unless you play at 4K dont see any reason