CPU Overheating after changing GPU
So you actually have an Intel core i5-10600 (non 'K') and it's hitting 100C during gaming.
FYI: 100C is the Junction Temp for that processor.
"Junction Temperature is the maximum temperature allowed at the processor die."
It might actually be that you are complaining about GPU temps, because the recent hardware change you've done is change to a new GPU (RTX 3060 Ti). I'd try MSI Afterburner and reducing its power limit.
By default, most GPUs fresh out of the box run at 100% power limit.
The latest RTX 30 series draw much more power, for instance my 3080 Ti I set it to as low as 45% power limit in MSI after burner.
+ an undervolt tweak as well.
Its no surprise that the latest RTX 30 series GPUs have high voltage transient spikes, and I wouldn't be surprised as well if it were the same case in Nvidia's upcoming love lace RTX 40 series too
Decrease the power limit by 5% and record in game temps and FPS
Keep doing this until you can no longer have an "acceptable FPS" by your standards, and then move it up a notch by 5%
That's where you determine what power limit to use.
If your game is complaining too little FPS, increase the power limit by 5% again.
I have experienced no crashes or errors or any FPS lags with 45% power limit, at least on my RTX 3080 Ti