This is what I will do. Just enjoy.Mine games around 65c, under cinebench it maxes at 77c, 5800x is known to be the hottest of the 5000 series due to the design of the CPU.
It will quite often boost upto 4.8ghz at 1.43 volts.
I just dont worry about it and enjoy my computer.
I've got it in eco mode for now. Think it limits total power to about 95w the same as my 3600. Everything I run is still at max fps (4k @ 60fps) and I've read people say you loose around 10% performance, but if/when I get fps dips I'll just turn the power back on babay.
Even at 10% loss I think it's still a bit faster than my old r5 3600, and will likely be in my pc for next 5 years or so. Unless games need cpu power all of a sudden
May get round to underclocking one day, if I can be bothered.