So why hasn’t someone created a batteries include JS library? I don’t program in JS on the backend so I don’t know how feasible something like that is.

Lodash but also, which batteries?

https://github.com/stdlib-js/stdlib was is one of several attempts at that, but yes the issue is that different people have very different views of what should be standard.

That doesn't seem like it should be an issue in practice? Rather than a single standard library endorsed by the language stewards if the community at large converges on a small handful of "standard" solutions that seems like it would satisfy the security aspect of things.

Everyone’s ideas of what batteries should be included differ

I, for one, root for AAA