I won't deny that vim has an "insane" feature count (particularly with plugins), but people who claim this kind of comparison typically vastly underestimate nano's own feature count and flexibility / extensibility.

And I'm surprised this usually comes as a surprise to people, given nano provides the ability for both internal (i.e. macros) and external scripts to manipulate its buffer. In principle you could even run non-interactive vim commands through nano if you really wanted to.