When fps drops to a certain level cpu spikes accumulating overtime(lower fps = faster accumulation)

I searched forums for this and didn't find exactly this report, but this has been happening since day 1 of launch and, probably, could be very important?
My setup:
5600x | 3060 (12GB)
Vulkan
Friend setup:
7800x3D | 4070 Super
DX12

If we limit background FPS and alt-tab from the game, the CPU spikes accumulate faster for both of us. If we limit it to the lowest FPS (1), it takes 5-10 minutes for the CPU to spike constantly to the point where mapping becomes impossible.

If somehow a similar effect occurs during the game itself (not on background) once fps go low each time, it's probably not the best thing that can happen.

As well, as I noticed, most problems with performance are related to:
- Proprietary Engine use
- AMD CPU + Nvidia GPU setups.

Examples:
1. Games on Creation Engine from Bethesda, especially recent ones that load system more (Starfield, FL76)
2. Path of Exile 1 and Path of Exile 2
3. There is 2 more, but maybe it's different scenario (not a big pool of games from studios) The Warhamme 40k: darktide and new Marvel team-pvp shooter.

Once I swapped 380x AMD to 3060 Nvidia, the difference in PoE1 and FL76 was barely noticeable, this how bad 3060 was underperforming. Overtime PoE1 become more stable, FL76 never did.
I do not remember other games/engines that cause such problems with similar setups, they were working as they should on my setup.

I really expected significant changes in optimizations since PoE1 and I still hope they will happen at some point.

I tried to play a bit after the patch and get back into PoE2, and it feel nice and fun, but encountering the same problem over and over discourages me from logging in, even though I want to play and try things. I just can't spend time on manual fixes that I shouldn't have to attempt in the first place.