I never thought this was some sort of taboo "nobody talks about this" topic, though. It's been openly and freely discussed for longer than I've been alive.
Although not entirely appearance related, Slow Ventures put out books and seminars to help founders not only look and dress better, but also be more intentionally professional, that seems to suggest there's a drift away from startup swag to sport coats.
That got me wondering if aesthetics like hair transplants, breast implants, and similar were as common in tech as they seem to be in Vegas, Miami, or LA, but that it's just not discussed as much.