Comment by bsder

> development/project dependencies are not and should not be managed by either of those but through project-specific means" on macOS, the standard Linux "one package manager does everything" approach feels simply wrong.

This predates macOS. The mainframe folks did this separation eons ago (see IBM VM/CMS).

On Unix, it's mostly the result of getting rid of your sysadmins who actually had a clue. Even in Unix-land in the Bad Old Days(tm), we used to have "/usr/local" for a reason. You didn't want the system updating your Perl version and bringing everything to a screeching halt; you used the version of Perl in /usr/local that was under your control.