While excessive dependencies is a problem and a liability, reinventing the wheel is even a bigger problem! NPM is there to solve a problem and when used correctly it brings HUGE benefits in many ways. Listing this as a benefit is clearly not understanding what NPM is for and part of the classical Not Invented Here.
[0]: https://github.com/totaljs/framework/blob/master/index.js
Edit: apparently that's not the right repo… looks like the comments are right that the source code for the messenger app is not on GitHub.
Total.js itself appears to be 15k lines in a single file with no dependencies, built and maintained by one guy (for the most part). Insanity.
Having no dependencies is great, but you need a rather large community of contributors to offset that or you end up with a stagnant undocumented bundle of source code.
But that could happen to any dependency. Arguably, left-pad was the least-worst dependency for "what happened" to have happened.