i have a 1080ti too and am waiting for the 4090 to upgrade. The main advantage of going to a 30xx, any, for you at this point is it adds RTX which the 10xx does not support. Do I really give a shit about RTX? Well, I don't even game on my PC (now I do on steam deck) so no, I don't really care that much. I think the 30xx line also supports DLSS which IS a big change but I don't know enough about it, but basically games can render at far lower resolutions but "look" better.
There is no doubt RTX is "better", but it basically makes reflections, mirrors, water, etc look more real. Does that really matter to me? not really lol, but you definitely see the difference
DLSS:
I think theres a new variant of DLSS, FSR (maybe AMDs?) so not sure how that plays into things either.