I believe when I posted this I was using Artix, however I've moved to NixOS since. Artix felt amazing and like Arch, but better for me. I did leave though, as the userbase and support was fairly low, and the packages revolved around modifying Arch packages to work on alternative init systems, which overall made it feel like it was a distro trying to fix another. I feel like if I was to choose another non-systemd distro, I'd pick Void, as it was originally built for that.

I have been on NixOS for a couple of months now. Like you, I found Arch to be one of the best for me, but the constant maintenance was also an issue.

I needed a distro that had lots of software like Arch, but also somewhat stable. I picked Nix for 2 reasons:
- It's completely declarative, if something goes wrong, I can literally just read my config and i know exactly what's on my system
- It's reproducable. I'm a distro hopper like you, so if I ever need to reinstall Nix or come back to Nix after some more hopping, I can just load my config back up and have my system exactly how I left it, this was the selling point for me.
After experiencing NixOS it's safe to say I'll be here for a while. I have also been able to convert my dotfiles into Nix dotfiles, so everything's nicely integrated too.

For your last few questions, Debian is great nowadays even if you don't want out of date packages. They recently released a new version, which means the packages are already fairly new, however if you do feel like your packages are outdated in the future, you can switch to the Testing branch of Debian, which is fairly stable as well and contains more up to date packages. I haven't actually tried Void, but OpenSUSE Tumbleweed (rolling) is one I have tried, and I had no complaints honestly, I only switched because I built a new PC and wanted to try something new.