Threads is having rapid success because it’s not really a new social network, it’s the Instagram social network in a different form. You “sign up” to Threads using an Instagram account and when you do, nearly all of who you follow in Instagram is on Threads and that gives the perception of overcoming the social network barrier. (The barrier of joining a new network hand having to build a new list of people to follow.) When you realize that Instagram is all about influencers and that nearly every commercial entity, actors, musicians, publications, etc. are influencers that brings a built in group of users who must sign up for Threads. I am on Threads but I probably won’t use it any more than I use Twitter, which honestly is not much.