What makes Bazzite-like uncommon is the degree of hardware testing and kernel tuning required to get some of the more exotic hardware fully working and stable.

Jovian exists for the Steam Deck and is probably the closest thing right now: https://jovian-experiments.github.io/Jovian-NixOS/

I am tempted to try making a "Nixzite" flake just to see how far it can get to feature parity with Bazzite, but again most of the story with Bazzite is the sizable community working on hardware tuning and kernel modifications. The catch with that flake would be a lot of waiting for the kernel to rebuild if I bring in the Bazzite patches, and that's just not a fun UX...