I'm not sure I'd define the atomic Fedora variants as "distros" in the traditional sense.
This is a bit of an oversimplification, but Bazzite, Bluefin, etc, are basically just Dockerfiles that use Atomic Fedora as the base image.
So you are basically getting a pre-built docker container that is "Fedora + various configs added on top", and then you are booting that docker image.
Since it's just a container file, anyone could theoretically just fork the Bazzite repo, make some changes to the Dockerfile, then push it to github + let github actions build a custom docker image.
So is that custom docker image a distro? Some would say yes, others would say no.
Interesting. So Bazzite could be, theoretically, remade as just a NixOS configuration file.