It's the least shitty of all other designs. It picked the best design decisions from existing package managers. By default it is project local (as opposed to global like what rubygems, pip, and others are), it's recursive and largely reproducible (fully reproducible using lock files). The resolution algorithm is also deterministic and simple, you can implement it in an hour.

Although other languages are catching up they have to do it as add-ons or third party tools -- for example python pipenv https://www.kennethreitz.org/essays/announcing-pipenv