Fríggin' finally. This distro is the one to watch, because unlike Silverblue or any other immutable OS, Vanilla doesn't build it's system image using some esoteric homebrewed standards. It uses OCI images to boot an immutable system.
Add distrobox
into the mix and suddenly you've separated the system from the user environment. That way user applications and system applications never need to touch, like at all.
Additionally if you can get one OCI image running on a bare metal system like a laptop or workstation, you could probably do it with others as well, meaning that as long as the system itself contained the tooling to rebase images, you could "distrohop" without having to delete any partitions or reinstall in any way.
You might need a process for that specifically, but it it possible - and being able to hotswap Linux distros, whereby going back is a reboot and selecting the previous image? Yes please.
There are several more immutable systems, like the afformentioned Silverblue (rpm-ostree), MicroOS (transactional-update) and NixOS (the programming language and environment that can spit out a system known as "nix".. which is what I'm using now). But it's all very developer-centric - even if that is not the intention.
Vanilla is a desktop-oriented distribution, pure and true. The developers and community want an easy, safe experience for all which is what an immutable system can help with and will open a massive world to newcomers who don't care what a distribution is, because they can use any distribution they want - from a single command... but also, in the future, a GUI!
So massive, massive shout out to the Vanilla devs and community. When it's released as beta stable I might consider returning, but.. nix... well.. the power is just immense. Mmmmm. MMMMM!