BlueSky is the viable alternative to Twitter. It’s got a vibrant growing community that feels reminiscent of early Twitter
It doesn't feel vibrant to me at all. If anything, it began as an echo chamber on day one and doesn't seem to want to be anything else. As someone who has been on Twitter since early 2008, it certainly doesn't remind me of an early Twitter.
People tend to talk about things that are salient to them, and disruption of large media institutions hits that button squarely.