CPU limitations can be pretty painful and obvious even with the 4090, what do you expect with the 5090?
In several games, I notice occasional large dips in FPS in certain maps and certain situations with lots of NPC's, movement, geometry, etc. These are indeed just occasional, but watching CPU and GPU graphs on a second screen shows that GPU usage dips heavily in those situations implying CPU limitation, even though 95% of the game is just fine. Say from a typical 90-120fps to 50-70fps when the CPU has to do heavy work. I can live with it but I still find it annoying and the faster the GPU is, the more you notice it. I can imagine this could become a new trend for gamers to (rightfully or not) complain about if (when?) we get to experience it more pronounced.