Until recently, I used to repaste my CPU almost every year. I know I didn't have to, but when these modern CPUs hover around 85C while gaming, despite using a 360mm AIO, I'll gladly take every degree ...

Repasting is cheap and easy to do, generally. I'd give that a shot. While you're doing that, make sure no dust bunnies have built a nest in the heatsink fins. Modern systems will park cores and do ...