Examples (genuinely curious)? In my casual experience, it seems to be easier to use than gems or pip and has much larger ecosystem than anything else I have tried, which is the #1 selling point of a package manager IMHO. A good package manager (by my standards) should have:

1. super easy publishing 2. A package for practically everything you can think of and if not, see #1 3. Most of the market share for its particular language so that you can be reasonably sure a particular module maintainer has an up to date package