npm was great!
Yes, it really was, but it seems to have deteriorated, at least for me. The fact that the current most commented bug is open for 1 year and 9 months is saying something.
And then there is the general state of npm.
So maybe we need something that is compatible with npm, but delivers good network performance. Sure there are plenty of alternatives or extensions to npm that provide local caching. You can even setup a local npm registry or let npm.org charge your credit card for using one with enterprise support.
But why bother when Facebook (they do have some experience concerning networking, I hear) has released their own npm. It is called yarn. For me it fixed the networking issues I have been having with npm and also provides cached packages for increased performance. Sure, it still has some bugs, given it has been open-sourced 3 months ago. But where npm has broken our CI environment multiple times, it is worth trying out an alternative.