Node.js assert library vs. other assert libraries

According to node.js assert library documentation:

The module is intended for internal use by Node.js, but can be used in application code via require('assert'). However, assert is not a testing framework, and is not intended to be used as a general purpose assertion library.

I was looking at Chai as an alternative assert library (no BDD API, only the assert API), and at the end I see that the assert functionality is very similar.

Why Chai's assert library is a better assert library? It does everything than node.js does (beside being just more rich in terms of assertion available, but that's just syntactic sugar-coating). Even simple things like the total count of assert executed is not available on both.

Am I missing something ?