The fact you need a 4090 to touch 120fps on 1080p in 2023 is disgusting. That should be the minimum target fps for mid range hardware at the least.
Meh, game is bland anyway.
It's shitty code bound. Sometimes no matter how powerful your hardware is, software will perform poorly because it just doesn't scale. Writing complex software like game so that it can fully utilize current hardware AND actually run faster with better CPU/GPU can become very difficult once a certain complexity threshold is reached. It's easy enough to do for a small linear game even if it has exceptional graphics, but an open world sandbox game like ones that Bethesda makes is a completely different story.
That doesn't mean that it's impossible of course - Bethesda absolutely should have made a better job, but it's by no means an easy task.
I was able to get a consistent 70+ fps with most things set to medium, 1440p with a 3900x and a rtx 2080 with dlss2 and a mod that helps performance without any noticable dregredarion I can tell.
Ok sure, 1080p low settings, I can get away with a 4080 if I have an i9 13900K. 1080p high? Yeah, not even a 4090 with a 13900K will get you near 120fps.