It takes time to build what Twitter is, not Twitter 1.0 but the one we have access to today. Anybody can throw some code held together by a stick of big red and a purple glue stick, even sink all the money in the world for advertising, nobody is sticking around
Anyone trying to replace Twitter at the bare minimum has to do what it does well and do things it doesn't exceptionally. So it takes time.
The problem is Twitter might not make it until Bluesky takes off or Mastodon gets its act together, although more and more officials and businesses are creating accounts over there, they're only there until the real replacement shows up