Higher resolution is all gpu, not cpu. You can game on an i5 8600k and get the same (ish) fps at 4k as you do with the 8086k. You are fps limited by the gpu not the cpu.
The upgrade to a 10th Gen will have more benefit in the long run as gpus get stronger, (3080ti etc) but until you upgrade the gpu there's little actual 'now' benefit. The 10700k being roughly equal to a better IPC 9900k. 11th gen supposedly will bring pcie 4.0, but that's no help either.
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