I'm on the transition phase, but I think I have settled on CachyOS for my Desktop/Gaming Rig, and Debian for the NAS/Server. The logic behind the choices can be summed as:
I want my desktop on the as recent as possible because of games and drivers and performance. The less friction there is when it comes to games and playing with other people, the better.
For the NAS, though? Once it is setup, I plan to only touch it for upgrades and the less of a headache I can make those, the better. I am trying to do my best at writing things out so that when, in three years, I have to inevitably solve an issue or three, I remember whatever it is I did and why. More importantly, Debian promises to make upgrades of in-pattern software easy, and I will be throwing docker at everything else, so I am hoping I can just update the packages/distro on a schedule and minimize the maintenance burden.
We will see how it goes, though.