Random, unpredictable crashes. Please help.

[VeryTired]

Update: I've tried many things, including placing a lower thermal throttle on my CPU and underclocking my GPU. This has improved stability in some places, but I notice my CPU getting very hot right before the game errors out. I'm no longer erroring out as often in low-pop zones and instances, so it seems I can do eight-man content just fine.

That being said, I errored out 3 separate times during a Thaleia run earlier today, and S-ranks and Hunt trains are basically out of the question, as I'll error out pretty consistently even at bare minimum graphics settings. Next on my docket is changing out my garbage CPU fan with a liquid cooling system to troubleshoot if it really is a cooling issue. After that, my only options seem to be changing out the CPU (and motherboard, by extension) completely or just waiting and praying that Square either comes up with a fix, or hotfixes the game to stabilize it.

@Larirawiel I have attempted to find settings to lower the performance core multiplier in BIOS and using Intel XTU, but after looking for over an hour, I cannot locate settings which allow me to do that.

Thank you all for your thoughtful and helpful responses. If you've got any tips or further information, I'd really appreciate them, but I'm near the end of my rope, been spending most of my freetime just troubleshooting this game.

List of things already tried:
-Upgrading GPU and using a different brand (Nvidia to AMD)
-Upgrading my RAM from 16gb to 32 gb
-Upgrading my power source from 600w to 1000w rating
-Removing fullscreen optimizations, disabling v-sync, locking frames to monitor refresh rate (60 fps)
-Removing interfacing USBs like the one which interfaces with my wireless headset
-Turning off XMP and Intel Rapid Storage Technology in BIOS
-Turning off Core Isolation and Gaming Mode
-Setting graphics settings to their minimums
-Undervolting and underclocking GPU
-Lowering voltage on CPU
-Closing external programs while running (Firefox, Spotify, etc.)
-Uninstalling and reinstalling the game, including verifying.
-Hard reinstalling Windows
-DISM / sfcscan