"Naturally I emailed Peter Singer", boss move lol. Jokes aside, definitely agree that sometimes the initial reason for the interaction isn't what makes reaching out worthwhile long-term. Oftentimes it's just a starting point for thinking about things differently or exploring their field of work with newfound motivation.
Twitter is definitely underrated for career dev (including by me up until a few weeks ago). Perhaps someone could write a post about dynamics on the platform? I find it quite intimidating and infinite game-ish relative to emailing/DMs, and I wouldn't be surprised if others felt similarly.