Completely missed this, I apologise. I can’t say you’ll go wrong with those three if you’re moving away from Nix, though Pop!_OS I don’t have any experience with.
Arch used to be seen as the DIY distro but Archinstall has made that point moot. The main reason to go for Arch is if you want the bleeding edge and the AUR with its vast amount of packages. Just don’t go Manjaro, because it’ll cause you more headaches long-term: https://manjarno.snorlax.sh/
Though Archinstall exists, EndeavourOS is a good Arch distro if you want an easier Arch experience.
Fedora is more stable but it also tries to be cutting-edge. They tend to be the first to adopt systemd, Wayland and PipeWire by default. If you don’t mind, it’s a good stable distro. If you want a different desktop environment, check out the Spins: https://spins.fedoraproject.org/
There’s also Nobara which is basically Fedora For Gamers ™️. It adds a bunch of patches and tweaks to make using Fedora easy. It’s worked on by GloriousEggroll, who you might know for working for Red Hat, as well as his GE-Proton patches.