Yes, but each package manager has it's (dis-)advantages. It's great to have flatpak and docker to be able to run software on almost all distros, but the OS still needs a way to update.
Almost all immutable distros use multiple package manager.
NixOS is unique because it uses the only potent package manager (if we don't count that one reimplementation of Nix). Calling the others "package managers" becomes mostly a courtesy when NixOS enters the picture.
lalala with FS-level snapshots + flatpak + distrobox + a kitchen sink
When I used to build app packages internally I also built packages for our own python and ruby versions for our in-house software. The motto was: “system packages are for system software”. We weren’t writing system software, we were writing business software and shipping it, so why be dependent on what Redhat or Debian provided?
Universal packages are just an extension of this philosophy, and is why things like docker and app stores are such a success. Burdening the user with getting system dependencies right is worse than the DLL hell of the old windows days.
Usually people mean flatpak and other desktop-focused formats when talking about universal package formats.
Even docker images are usually built with traditionial package managers, except if they're built directly by Nix.
I agree that there won't be "the" package format, since they all have their tradeoffs. E.g. Nix updates need quite a bit of memory, so it isn't a good choice for resource constrained embedded use-cases.
Flatpak with OSTree or ABroot, the future is now. Although it would be nice if Silverblue would automatically create a container and install non-flatpak apps into it, then add desktop.ini files automatically:
Is it used for any serious apps? I saw they released the "cosmos" which is very impressive but mostly seemed like basic utils that were already available in Linux/Mac?
Frankenstein is a surname. The mad scientist's name was Dr. Victor Frankenstein. Since the monster wasn't endowed with a first name, the only name it would have is Frankenstein: the same last name as its father.
You should at least read the source before you spout off. The monster's first name is Adam. And as an aside he speaks and reads three languages. You probably think he was slow and clumsy too.