I think the point is that an i7, even from ~15 years ago, is probably sufficient for most gaming needs, especially if the game is primarily GPU-bound.

As long as you give the older CPU enough RAM, an SSD, and a good GPU, it probably is sufficient unless your doing sim-heavy games where you want the simulation speed to be maxed out (e.g. HoI4 later years max speed simulation)

The CPU will be a bottleneck even if you use ~7 years old RTX 2060. Anything newer just wouldn't work.

Honestly buying a 15 years old CPU is just an own goal when it will be outperformed by any modern budget i3