I wanted to spend some money on upgrade. Jump from RTX 2080 to Ti is just too much for me. I cant justify cost of RTX 2080Ti. Only thing which i can upgrade from my point of view is CPU. My thoughts was i7 9700k looks more futureproof because of OC capability and solid eight core against six core + HT of 8700.
I never OCed and i am not sure how much performance gain i can expect. Right now i dont have Z board.
Then don't bother with it; to make use of a K-series CPU you need a Z motherboard, unfortunately. You can still OC any CPU in an H-series, but you'll have to know what you're doing and it's not as easy.
And don't underestimate those threaded cores from the i7 8700. I believe the scaling factor for each HT core is around ~33%, so if you want to put it in "hard" numbers, your i7 8700* is equivalent to a ~8 core CPU already; maybe a bit less than 8.