"I’ve only very rarely seen a node.js project that wasn’t on github."
To an extent, that's due to npm's git integration and lack of strong free (for open source) git hosting alternatives. You can specify a git endpoint for a module import.
> You can specify a git endpoint for a module import.
But you lose some of the magic that comes from expressing dependencies through semver versioning. You can publish multiple versions of a module sourced from git, of course, but that takes a lot more manual effort for publishers than than it does to publish on npmjs.org.
To an extent, that's due to npm's git integration and lack of strong free (for open source) git hosting alternatives. You can specify a git endpoint for a module import.