Just watching a video of various games and the FPS difference between 4,6,8 cores.
6 and 8 no difference but both equally faster than 4 cores. Same setup for the tests except the CPU core number.
View: https://youtu.be/AqBl9frFESI
Hi, first of all some of those games are really old, even the video is from may 2018, that over 2 years ago. As others stayed already, those benchmark do not really show the whole picture.
If you are only gaming in 2020 and not doing anything else, no discord, no browser, no streaming, nothing but the game you are runing, then you may get away with 6 cores/6 threads if you have one, for example the i5 9400/9600K.
If you are building new, and wana be on the safe side, get at least a 6 cores / 12 threads cpu like the Core i5 10400/10500/10600/etc. or the Ryzen 5 2600/3600/etc.
The Core i7 8700/K with its 6 cores / 12 threads, or the 9700/K/KF with its 8 cores are nice old cpus cause even today still have room to breath.