It’s not about hours of interaction. One poor sales interaction can hurt one transaction. One poor requirements interaction can have years of software consequences.

So what? Introverts are perfectly good at doing that. And they're happier than extroverts at a job where there's less of that.

Being comfortable meeting new people every day, constantly, outside the company vs. being comfortable interacting with people you know within your department and occasionally elsewhere in the company may divide people, but should it really be called extroversion vs. introversion? Is this the normal meaning of the words?

If one person is sustained by issuing fake smiles to strangers, and another by exchanging real ones with colleagues, how is that extroversion vs. introversion?