Yes, indeed - and the dependency is literally right there on the technical level. For years, you've been able to specify a version of a package as a github repo's branch HEAD.
npm i some-package username/repo#branchName
npm i some-package username/repo#branchName
npm install username/repo#semver:^1.2.3
The big problem is that lots of Node.js modules don't push their tags, so there are issues on lots of repos begging maintainers to push their Git tags so that we don't have to use the npm registry.JavaScript is an interpreted language -- as long as you're only downloading source code from the registry there's really no reason to use a registry instead of the plain old Git repository.
With NPM acquired by GitHub, I can imagine them "filling in some steps" by leveraging the fairly new Actions feature, so that repos can provide built artifacts, the same ones as published on NPM. The deeper integration will be an interesting development to watch.