Honestly don’t feel too bad. I JUST tried switching full time to Debian bookworm with a 3070ti and I had the EXACT problems you describe. I tried built in drivers. Debian Nvidia drivers. Nvidia drivers straight from Nvidia, nothing would work. Was getting like 60 fps in overwatch and it would dip to 20 frames constantly. It was unplayable. I couldn’t even get my 4 monitors connected at one time no matter what I tried. Ended up going back to windows 11 with the decrappifier unattend file. Back to 170 frames easy. I am convinced the only way to dodge this is with an AMD card. My next computer will be AMD graphics for sure so I can finally switch for good. Sorry about the long rant but I was so frustrated with it! Don’t ever doubt yourself and swapping to the AMD card! Lol.
Honestly don’t feel too bad. I JUST tried switching full time to Debian bookworm with a 3070ti and I had the EXACT problems you describe. I tried built in drivers. Debian Nvidia drivers. Nvidia drivers straight from Nvidia, nothing would work. Was getting like 60 fps in overwatch and it would dip to 20 frames constantly. It was unplayable. I couldn’t even get my 4 monitors connected at one time no matter what I tried. Ended up going back to windows 11 with the decrappifier unattend file. Back to 170 frames easy. I am convinced the only way to dodge this is with an AMD card. My next computer will be AMD graphics for sure so I can finally switch for good. Sorry about the long rant but I was so frustrated with it! Don’t ever doubt yourself and swapping to the AMD card! Lol.