I agree that high PCH is not good in a perfect world, but like Murph says, that's just the way it is. I've seen reports of 690 chipsets running at 70-80C even in Windows, higher in games.
If you can get it below 60C then you're doing well. You could add a small fan pointing towards the chipset as well if you want. That can reduce temp by a further 5-10C. The 'best' way is to strip out the heatsink, remove the plastic cover and replace the thermal pad with a better one. However, you might not have a warranty left, so to be honest, try to avoid doing that unless out of warranty.
I've added a fan and my chipset now rests typically at 56-59C and rises to 65C in games. I'm happy if it stays below 60C most of the time, but really, even if it's higher then don't be concerned. These chipsets can run hot without problems and I've never heard of one failing (although I'm not sure how you would tell, apart from not booting?)
Z690 Hero, BIOS 2305, ME Firmware 22.214.171.1246, 7000X Case, RM1000x PSU, i9 12900K, ASUS TUF OC 3090TI, 2 x 16GB Corsair RAM @ 5200MHz, Windows 11 Pro 22H2, Corsair H150i Elite AIO, 4x Corsair RGB fans, 3x M.2 NVME drives, 2x SATA SSDs, 2x SATA HDs.