"sciency people" is a huge community, I think even within computer science (which is not a science), each community have their own perferred platform.

Algorithm, foundation, and automata theory people often don't have social media or on mailing lists; more foundational fields like programming language people often perfer Mastodon; more flushy system, network, and security people often are on bluesky; AI/ML people, of course, are often found on xitter.