You should learn docker if you care about self hosting stuff though. You might lose 1 day learning the basics of docker, but the practicity of being able to spin up services just to test them it’s well worth it.
Personally I use Immich for photo management, but not sure it it’s packaged as an RPM, and even if it is you’ll need to setup the database yourself. Nextcloud also possibly works but again setting Nextcloud without containers is a PitA.
Someone asking for a service to self host that refuses to use docker is similar to a person who wants to run a server but refuses to learn CLI, yes it can be done, but you’re making your life hard for no purpose and everyone else will just give you the simple solution.
NixOS packages only work with NixOS system. They’re harder to setup than just copying a docker-compose file over and they do use container technology. If the idea is to remove complexity from the setup, NixOS goes in the opposite direction.
Also without containers you don’t solve the biggest problems such as incompatible database versions between multiple services.
I stand by what I said, I can give a 2 step tutorial on setting up any docker system (copy this compose file, run up on it), anything simpler than that wouldn’t be as robust in terms of configurations.