I am wondering the same thing. I am currently using an overclocked (5GHZ on all cores) 8700k. In combination with a RTX 2080. I would like to upgrade both, the GPU (to RTX 4080 when it comes out) and the CPU either to 13600k or 13700k. But I can’t do both upgrades at the same time.
I think a GPU upgrade would give us the greatest quick FPS improvement, but the 8700k might be slightly bottlenecked at least for my gaming in 1440p. Actually, I am trying to find out how bad the bottleneck would be if there is any. My 8700k is not bottlenecked at all…CPU never is over 30 to 40%. While the RTX 2080 is running at 100%