It has been some time since I gave this a proper look. Do you use this yourself? If so, would you be so kind to share some of your experiences?

OP, another vote for this one.

It addresses your concerns in a wonderful way:

• Reliability; While it’s far from unique in this regard, I’d argue that the uBlue distros are one of if not the most reliable desktop Linux experience that’s currently out there. You know most of the drill already (read: built-in rollback functionality, clean base system). But, the uBlue project has some aces up on their sleeves that (to my knowledge) are pretty unique:
  • “Ninety (90) days of image archives allowing for flexible rollback options.” The images are stored online, so they don’t even take space on your device.
  • Shared community maintenance, i.e. even if upstream has a rare fuck-up, you can trust on uBlue’s maintainers to deal with it without you even noticing. For a recent example of this, we got this.
• Access to the AUR; while Distrobox can be installed on any distro, uBlue projects come with perks that make the whole experience better than it’s found elsewhere. From quadlets that have been properly setup from the get-go so that you don’t have to (additionally) maintain those distrobox containers, to even minor things like including Boxbuddy OOTB to make the transition as easy as they come.
• Setup for Gaming; It goes without saying that Bazzite is excellent for gaming. It’s gaming-ready OOTB and includes (almost^[1]) all the performance tweaks you’d wish.
• Setup and forget; I (almost^[2]) don’t know any other distro that better embodies this than Bazzite (and its other uBlue-relatives).

All in all, I think Bazzite is definitely worth a look. Consider installing it and setup to your heart’s content. If -at any time during or after that process- you come across an insurmountable^[3] issue caused by its atomic/cloud-native/‘immutable’ nature, then you can check it off your list and look elsewhere.

1. CachyOS is still superior in this regard by doing a better job at inching out (literally) every performance gain out there.
2. Perhaps Endless OS does an even better job at this, but that would be a bad recommendation for all the other reasons.
3. Before giving up, if you wouldn’t have done it by then, at least consider contacting the community through their Discord server. They’re very helpful. FWIW, Bazzite has pretty excellent documentation as well. (Even if it ain’t as exhaustive as the even more impressive ArchWiki. Granted, it doesn’t have to be as expansive.)

Literally said they don’t want immutable.

At best, they might have implied it. (But I don’t think they do.) Here are the (relevant) snippets:

I honestly have even been looking into some of those immutable distros (that’s how much I don’t want to be fixing my system. I’m tired, I just want to use my system to get work done)

I was once told by some kind soul to use an immutable distro and setup “distrobox” on it if I wanted the AUR.

Seems cool, but it’s unfortunate that the project doesn’t seem healthy. Last commit was 5 months ago. Furthermore, its maintainer has even explicitly mentioned that the future of its project is uncertain. At least, we gotta give them credits for being transparent.

I see that they have a Nvidia image and they actually recommend if possible to stay away from Nvidia but does it work well with Nvidia or AMD GPUs?

Just to be clear, the Nvidia images support Nvidia GPUs well and the non-Nvidia images support AMD (and Intel) GPUs well*.

I was wondering if VanillaOS would be a good fit for my parents, which actually, it might be. They have very basic needs. All their apps are on Flathub.

Have you considered Endless OS? It’s another atomic distro based on Debian. However, it’s based on the Debian stable instead of Debian unstable. Futhermore, instead of making their own tools (like Vanilla OS has done), Endless OS relies on established ones instead (like libostree, which is also found on Fedora Atomic).

Any particular friction with GPUs?

Not that I’m aware off. IIRC, both secureblue and Bazzite rely majorly on this for their hardware enablement. Hence, I don’t think this should be significantly different between them.

I see that they have a Nvidia image and they actually recommend if possible to stay away from Nvidia but does it work well with Nvidia or AMD GPUs?

It should support both well, yes.

Can we maybe tinker it to get some of the things that we have in Bazzite?

You definitely can. Anything in particular that wish you to get over from Bazzite?

Regarding Caps Lock, the user named “warmaster” only relayed their own experiences. FWIW, I can relate to their experience. Ever since my switch from Windows to Fedora Silverblue, I haven’t experienced any difference in Caps Lock functionality; it’s literally the same as I was used to on Windows. And thus the very same you* said you liked. My repertoire of distros ain’t as impressive as some notorious distro-hoppers. However, I don’t recall this to be different on Arch, EndeavourOS, Nobara or other images within the Fedora Atomic ecosystem.

Edit: added “you”

it would be important for fixing bugs, I guess?

I think this is where the sandbox~y nature of Flatpak comes in. It doesn’t really care for the distro-environment, because it creates its own distro-agnostic one; ensuring that software continues to work regardless of the shit-show going on elsewhere.

It is for this and other reasons that some developers vouch for Flatpak.

Very interesting! Thank you for mentioning this! I suppose including a link to the article in the main body would help alleviate this issue.

I mean, like… To which Manjaro fuckup are they referring?

Obviously, I’m not the author. But if I’d have to guess, their answer would likely be “Yes.”.

Author’s disclaimer:

“Flatpak is NOT a distro, but that’s what Steam reports when it’s running on Flatpak, and Flatpak being distro independent we report it as a separate environment, if that makes sense. Feel free to ignore it if you wish.”

The only thing is that there’s not a lot of distro-specific guidance out there

I’m genuinely curious to hear what’s missing here.

Not OP. But, FWIW, I’ve been daily driving secureblue for over a year now. And it has been wonderful experience.

Note that, by virtue of its superior security model, preconceived knowledge may not translate well. However, if you read its documentation and FAQ, then I’m pretty confident that you should be fine. Thankfully, if something’s not clear or if you’re facing issues, then you’re in good hands through their Discord.