I have a TV which says it supports 4K 144Hz and right now I run an old laptop as a media server/desktop to it, which can only handle 1080p. I wish to switch to some NUC/mini-pc that run a linux desktop in 4K and run media flawlessly on it.

There are two things that I get confused about trying to find something that suits my wishes:

1. How do I properly find out if the hardware can handle this? Like a rpi5 can handle 4K video playback with like librelec, but a 4K desktop distribution is laggy and slow. Is a CPU only enough, or do I need dedicated GPU? Should I be looking at the Ultra Core series from intel, does it have good linux support?
2. Are my wishes on hdmi 2.1 level troughput? Which may not work on linux? Reading about hdmi 2.1, then it says that the hdmi forum forbids open source support for hdmi 2.1, does that mean there are binary blobs for linux that will work?

Is there anything else I'm missing? If you run a linux media server, what hardware and dist are you running?