Intel or Amd, 6/12 or 8/16 thread cpu, anything modern or modernish. 10th/11th/12th gen Intel 10600/10600k, 10700k, 11400, 11600/11600k/11700k. Ryzen 5000 series 5600x/5800x. All of which are modern or modernish, enough for your card.
7700 is the maximum you can have for your motherboard so new cpu means new motherboard, different socket.
Just on Dying Light2 though, you are running Dx12 in that game? I play it and Dx12 gives more performance than Dx11. And try running no antialiasing, no dlss. Use DSR 2x factors in NvidiaCP manage 3D section to increase resolution ingame. Choose that resolution DSR incorporates in the actual game.
Can you elaborate on that? I have had the same 8700k for the past 3 generations of GPU's (1080, 2080s, 3080) and every time I upgrade I get to crank the settings higher while also getting significantly better fps in the same games. Do you just mean in a scenario where the CPU is maxing out? I play at 1440p though.