Most people who have the money to invest in a 4090 are also going to invest in a beefy CPU. It's not a secret that CPUs are bottlenecks for games within the gaming community.
I mean its only common enough that the headline grabbing feature of the markets undisputed largest GPU vendor is a feature literally designed to reduce its impact as a bottleneck.
Disagree. Many games are ultimately limited by the performance of a single hot thread (often physics). Some things just don't parallelize, so throwing 8/12/16/24 cores at them doesn't help..