I really wanted to try an arch-based immutable OS. I came across what is now known as "ashos". It was (and still is) in early development. It relies on btrfs snapshots for its anti-hysteresis properties. The code is mostly Python, but it just uses os.system calls everywhere and often doesn't do anything to verify exit codes before continuing to the next command. The main developer doesn't seem very interested in following best-practice conventions of the language he's working in, so that's where my interest unfortunately ended.
I follow Jorge Castro on fedi, and I see a lot of the points he makes in promoting not only ublue but also immutable distros and related containerization tech in general. To me, it seems like a lot of added complexity and excitement to work around distro-specific problems that I do not have.
Would it be cool to be able to instantaneously re-deploy my machine's entire environment? Sure, but I can count on one hand the number of times I've borked an Arch install in the thirteen years I've been using it: That number is zero.
For me, the web client keeps re-rendering itself for apparently no reason. It's a very janky experience.