1080p, your GPU is overkill for that. Might consider a monitor upgrade there as well.
If you are using your PC for work related things as well as gaming, I highly recommend the i9-10900F. Relatively cheap for a 10 core CPU. Runs 4.6Ghz all core, and 5.1Ghz boost on a single core..
i9-10850k would be the overclocking equivalent, or the i9-10900k for a little more.
That or a Ryzen 5900X for 12 cores.
i7-11700 is fine as well. I do suggest upgraded cooling with either Intel solution. If you grab a Z class board, no big deal to remove the power limits. My i9 pulls 192W under a full load.
Ryzen 5800X is also a good alternative, though there are a few cases where software has not been optimized at all for Ryzen.
As for waiting on Alderlake or Zen4, probably looking at mid-year 2022 for desktop parts, late 2022 for the latter. First generation DDR5, may not go so great. They have moved power regulation to the memory sticks and are already talking about memory cooling being needed. I myself plan to wait for the second generation stuff after they've worked it out. (Bonus it is ECC memory)
4th gen i5 is pretty dated, so you would see a huge leap in performance just going to a 6 core 12 thread system, let alone 8, 10, or 12 cores. Certainly needed with an RTX 3070, particularly if you are after high refresh rate gaming.