You know, distrohopping is overrated. If your distro works for you now, you don't really need to switch. Other distros may have slight differences, but all in all it usually is just changing some problem for another. Most distros will be fine.

Having said that, I think Debian Unstable ticks your boxes. Most rolling releases will do what you want.

If your using Manjaro unstable, why not go with Arch or EndeavourOS directly? Manjaro has advantages through it's slower rollout of updates, but unstable doesn't have those. So EndeavourOS is mostly the same experience, except of reduced complexity since Manjaro has more custom tooling.

NixOS sounds perfect for your use case.

Of your key features it has:

• A simple GUI installation process
• A very large package repository (the largest, in fact)
• Frequent updates and bleeding edge software through nixos-unstable and nixpkgs-unstable channels
• The ability to try any desktop environment you like by editing one or two lines in your config
• A very supportive and active community

Additionally, if you like to reinstall frequently, NixOS negates the need for maintaining an installing/config script since the singular configuration.nix file that you edit to customize your system will rebuild the exact same system on another computer. For example, I copied my configuration.nix on my PC to my laptop and now they are exactly the same, packages and all.

NixOS may seem a little daunting at first, since it has often been referred to as an "expert" distro with a steep learning curve. Don't let this fool you though--despite NixOS' unique advanced capabilities--it is actually quite straightforward and simple to use as a desktop machine. Speaking from personal experience as a perpetual linux noob, it's really not difficult and the benefits and stability of it far outweigh any small hiccups you might encounter initially.

If you have the motivation and are looking for something new, you could try NixOS.

Manjaro is always the problem, use EndeavorOS or Garuda.

I'm extremely wary of Manjaro in general. I don't personally care for their approach to package management (delaying the Arch core repository but still relying heavily on AUR seems like a recipe for instability to me), and the Manjaro team have shown themselves to be less than reliable.

All that said, if you're mostly happy with Manjaro, then Arch or Endeavor might be the way to go. They use the AUR (Arch of course is where the AUR started, and Endeavor is based on Arch, but doesn't delay or muck with the Arch repositories the way Manjaro does).

Endeavor is super easy to install. Cinnamon is one of the available DEs on the installer image, and their system tools are good. They also have an active community and haven't (to my knowledge) accidentally DDoSed the AUR with an update, so they seem more competent than the Manjaro team.

Arch, of course, is the forerunner to Manjaro. It's slightly more difficult to install than Endeavor, using either the archinstall script or the Arch Method, but kind of worth it for the level of control it gives you over your system. Since you make your own post install scripts, I don't think you'd have much issue here. Cinnamon is (of course) available, and the community is extremely knowledgeable, although they do expect you to be able to RTFM and perform basic troubleshooting on your own. As an added bonus, you get to say "I use Arch BTW" with a sense of either irony or smug superiority. Both are good.

I use Fedora, BTW. It has Rawhide for bleeding edge, Copr for expanded packages, and a Cinnamon spin. I don't think it's a good match fr what you're looking for, but it might be worth looking at.

An up side to all three of these is that you usually don't need to reinstall your whole system multiple times a year to keep it clean and running smooth. That was my experience with Manjaro back in 2016 or so, though, so I can see why you do it.

Not sure why you want to switch if Manjaro works for you. If you want to, you can try Arch (if you want to get your hands dirty) or endeavourOS which I have been using for over a year now and love it. You also have fedora, Debian unstable, opensuse tumbleweed. Moving distros in general is becoming useless honestly. You can replicate anything on any distro. I stuck with Arch and its derivatives because I am just used to it and how it works. Also, I like the AUR a lot, as I'm not a big fan of flatpaks/snaps and all that universal packaging (just a personal choice, nothing against those).

you may find other repos a bit lacking compared to manjaro's since they have a few things in there that are added on top of the arch ones, aur is the same across all arch based distributions and aside from ubuntu, most other distributions will have fewer useful package than those two.

you could try garuda wich integrates aur package in the system's repository through the chaotic-aur repo, and they do have a cinnamon flavor

Seems like what you like is Manjaro and what you have issues with is Cinnamon. Can't you just switch the DE? I've been running Manjaro KDE for a while and have no complaints, I like KDE and I like Konqi

You said a bunch of things you like about cinnamon, and nothing that you don't. Is there something motivating you to switch?