Do not bother about this bottleneck sort-of-hoax people have been spreading about lately, bottleneck is just how a computer works, there are bottlenecks everywhere, but it seems that cpu and or gpu bottleneck haunts people for some reason i cannot understand.
first, you have a 6/12 cpu, that alone is perfectly fine, we just currently started to (heavy quotes) fully utilize 4 cores cpu, so 6 /12 ones gives you the breathing room you need, but of course this isnt only about cores, so, yes, a 10900k will give more fps on a 3080 than a 6800k, but so what? despite having no benchmarks around, its 99% guaranteed that the gpu that will give you the most frames is indeed 3080 (not considering the pointess 3090 for now), so if you want it, go for it! understand that a cpu outputs what it outputs, and a real bottleneck case would only manifest if you are having problems running your games, with that combo? you wont have,