Fancy, expensive processors are fun, but for most people who just want to build a decent middle-of-the-road PC for gaming (and anything else), the best advice is usually to buy a Core i5 or Ryzen 5 ...
When looking at used PCs, there are words that provide a sense of security. Core i5. Yeah. It sounds fast. It's better than a Core i3, and it doesn't seem as expensive as a Core i7. It's just right.