My PC is not performing as it should

Dear u/Daddy_Spez, i built a new gaming pc right before the pandemic and i dont think it performs as well as it should. I spent a good chunk of money on it since i always had the dream of having a good rig since i was a kid and now that i earn my own money, i made that dream possible for myself.

I noticed it almost immediatly but it was never "that bad". now that is has been about 2.5 years and the hardware became a bit more "dated" its pretty obvious. One thing i noticed that it seems like i have some kind of bottleneck. Lets say a game runs at 45fps most of the time, absolutely nothing makes it increase that much after that. It's \~the same, no matter the graphics settings. i could be playing a game on ultra graphics and only get about 5fps for switching to the lowest possible graphics.

It's not as apparent when im not playing, under normal workload it seems mostly stable with some slight infrequent stutters (almost not noticable).

My Specs:

\-AMD R9 3900x

\-RTX 3080 Gigabyte OC

\-32gb 3600Mhz RAM CL16

\-1000GB M.2 2280 PCIe 4.0

\-Gigabyte X570 Aorus Master

\-2x 4TB Generic HDD for Data

I install everything i regularly use on the M.2 SSD, i update graphics drivers and everything except windows (i just like 21H2.. but i've tried other versions to no success).

Just about every Game performs poorly (stutters, bad fps, crashes), i have friends with worse rigs who are getting much better performance.

I already tried completely reinstalling a fresh windows per boot stick, resetting bios settings, several "helper"-programs such as process-lasso and letting my gamesettings be recommended from geforce experience. I've also looked at temps which seem to be ok (mostly \~60 celsius when normal working, up to 80 under extreme stress). I haven't changed any BIOS setting apart from enabling XMP, RAM is also running on the right speed.

I'm actually out of real ideas and dont know what i could do or change or test to get to a solution.