I understand this from the developer's perspective - but from a user's perspective, it's horrible UX. I usually don't care much which language the programs I use are written in - however I would very much like a single place where I can view, manage and update all installed packages. This does not work if each package manager keeps its own list.
It also feels ridiculous to have to install another package manager if you only want to have a certain command line tool.
Maybe this could be solved by a sort of meta-standard for package managers, so the OS has at least some way to aggregate all package managers and language-specific packages installed.
Of course, as always with meta-standards, you might fall into the XKCD trap...
Containers solve this nicely; developers are free to use their language's package manager to build container images which the user can manage via a single interface. Of course, this means you often have more duplicate code on your disk and the update model changes, but that's alright for me.
It also feels ridiculous to have to install another package manager if you only want to have a certain command line tool.
Maybe this could be solved by a sort of meta-standard for package managers, so the OS has at least some way to aggregate all package managers and language-specific packages installed.
Of course, as always with meta-standards, you might fall into the XKCD trap...