And around 10% of the market has a GPU that meets the same tier of requirements for Civ 7. The people who buy a high-end GPU often also buy a high-end CPU, because it's possible.
Also, I don't think gaming-optimized CPUs are that important. As far as I know, it's a concept AMD introduced in 2022. Until then, gamers usually just bought high-end consumer CPUs, and Intel users still do. And those use core counts to differentiate the top models from lower tiers.