@evan None of these: I use Mastodon.
Twitter in the past was unmatched as a source of discovery. Then Musk came in and progressively there were enough web platform enthusiasts who finally arrived on Mastodon. But outside of the web platform, it’s still missing a bit the diversity of Twitter pre-X.
LinkedIn is an absolute source of bad advices for developers. I don’t know about Reddit and Hacker News.