Linux

NixOS can’t configure desktop environments, such as Gnome and KDE.

That's because those DEs are configured via config files in your home and NixOS is only about system management; it does not touch your home (other than creating its directory).

If you want to configure home files, you use home-manager which has some support for configuring those DEs.

NixOS is stable, so NixOS works best in server environments.

NixOS has a "stable" version and a rolling one. The stable one is bi-annual though with no LTS, so it's more of a Fedora than a Debian.

The rolling channel ("nixos-unstable") is where all the actual development happens. It has similar stability to Arch, though we do more QA through our CI.
You cannot get an update where the e.g. bootloader breaks. That just doesn't happen for us because the update must have passed a test where the bootloader gets installed in a VM and then booted before it can reach you.

there was a point where the NixOS stable branch… broke. I’m not sure what went down, but I think that a manual merge train messed smth up.

Stable is pretty damn stable, we usually only backport security fixes and the odd bug fix. If a bug fix introduces new bugs, that could "break" stable in a way but stable "breaking" in a major way is pretty much unheard of. Again, as I mentioned, basic things like networking or filesystems are tested by CI.

You're going to have to be a bit more specific than that.

There’s also the situation where they store the entire package store in Amazon S3 because someone else paid for it. That someone disappeared, and they expect the community to stem the costs now. If they don’t pay up, NixOS stability is once again dead.

This is way overblown. That someone is still paying. They've just said they don't want to continue doing so (which is absolutely understandable) and asked to find an alternative soon. They're not suddenly cutting us off; this is not an immediate threat.

The NixOS foundation has funds set aside to continue even this very expensive way of hosting the cache for at least a year. Even if they were to suddenly cut us off (which they won't), we'd be fine.

The post you linked is a call to action to find solutions to reduce that cost and to find a way to sustainably finance it without relying on a single sponsor.

More critical would be if the CDN in front of the S3 Bucket (which is what actually serves most paths to users) were to disappear but the provider of said CDN is directly sponsoring us they haven't shown any sign of wanting out. People are brainstorming to find possible alternatives to that setup aswell though, just in case.

We're fine. Even in the worst case scenario, we'd be fine. In the migration time frame, there might be hiccups here and there but that's not too concerning or special.

I feel like the tooling is all over the place. There are many ways to do one thing, and you never know what’s the right thing to do.

Yeah, tooling has been in a bit of a weird spot where we're currently in the transition between the old and the new way of doing things. The new way isn't finished yet however an is still unstable.

The "old way" works just fine though and you can ignore all the new stuff if you don't like instability. I myself still use the old way. Sometimes I use the "new way" too because it's got some convenient features.