But, this is exactly what I'm saying. you start with a small, focused library that contains everything you need, which is usually fairly minimal, so that library is small. but then, along the way, you find yourself wanting, so you add a library that adds support for that specific thing.

I didn't add sinon-as-promised for fun, I added it for in-memory sequelize integration tests. same for all the other libraries I mentioned.

My point is that by keeping libraries small, you will end up with either more dependencies, or a lot more hand-rolled code. Neither of these things are inherently bad or good, and I'm not defending them. What I am trying to do is explain to the commenter why the node ecosystem seems to have such an emphasis on package management and the tooling around that.