980Ti & Big Sur? Catalina?

Hi. Its been a while. Ive been happily running High Sierra 10.13.6 on my i7-9700 & 980Ti setup for about a year and a half now for video editing and many other productions. In 2021, it is slowly beginning to show its age in software. I need to put something newer on there so that I can stay with the times without having to spend 50x my life's savings on a Mac Pro. I know the last time anything above high sierra does not work with Nvidia GPUs, but I have been off reddit for a while so I dont know the advancements (if any) that have been made and I think I need a bit of a catch-up. I frequently find myself running Final Cut Pro X and need the GPU power over my 2017 MacBook pro (editing 4K is really really slow for me on that)

I also use Optical audio on my system. I dont really care about the other inputs and outputs on my system other than USB3.0 and USB-C. They're there and certainly nice to have functioning.

Dual display setup, ones a giant touchscreen, ones at a desk across the room, I love my wireless keyboard and mouse :)

System specs:

Intel i7-9700 980Ti Pascal 6GB (Many, many many USB devices) Dual screen setup @ 1080p each (one is custom touchscreen) 500GB 850EVO SATA SSD (macintosh boot drive w/clover and High Sierra 10.13.6) 1Tb NVME SSD (partitioned 50/50 as a boot drive for Windows and a scratch drive for Final Cut) 2TB Seagate FireCuda SATA SSHD (for windows games) 16GB ddr4 Ram (across 2 slots I think) my mobo is an ASUS ROG Z390-I gaming (mini ITX form factor)

It does have USB-C, no thunderbolt.

Built in wifi and bluetooth that is still original to the board (some intel chipset, it does work in high sierra, surprisingly, bluetooth included as long as you boot windows first then restart into macos)

As you can see, I have a pretty well specc'd system and I hope you can understand why I want to upgrade my software, but not the hardware (GPU) also, as with all the stuff thats going on surrounding 'shortages' with graphics cards.

I was also wondering about compatibility with newer RTX 30 series cards, too just for future reference.

Please do not hesitate to ask for more information I may have left out, my bedroom is the computer at this point so it is certainly not hard to find.

Also, i am a bit dyslexic so i might sound like english isnt my first language, but it is lol