Here is a thought experiment (for devs who buy into package managers). Take the hash of a program and all its dependency. Behavior is different for every unique hash. With package managers, that hash is different on every system, including hashes in the future that are unknowable by you (ie future "compatible" versions of libraries).

That risk/QA load can be worth it, but is not always. For an OS, it helps to be able to upgrade SSL (for instance).

In my use cases, all this is a strong net negative. npm-base projects randomly break when new "compatible" version of libraries install for new devs. C/C++ projects don't build because of include/lib path issues or lack of installation of some specific version or who knows what.

If I need you to install the SDL 2.3.whatever libraries exactly, or use react 16.8.whatever to be sure the app runs, what's the point of using a complex system that will almost certainly ensure you have the wrong version? Just check it in, either by an explicit version or by committing the library's code and building it yourself.