I've been in managerial role for a while now, so I can appreciate the "other side", as a recruiter/interviewer. It's hard because you're having to make judgement calls with very limited information, so I can easily empathize.

But as a recruiter or boss, the onus is on me to suss out the data I need. Given that introverted people have always existed and will always exist, it would be ignorant and lazy of me to only pick from the crop that puts themselves in the spotlight for me. Not to mention the very obvious fact that a lot of people are very good at selling themselves, even when they have nothing to offer.