They work so well because Big accounts within a Network retweet them and there's lots of replies of Premium users. What matters the most for X algorithm is something called "Post watch-time", this is how much time people spend looking at a post. Threads like these have a big retention time because people will Open a thread, scroll through replies which builds up the retention. The longer people spend on your post, the better it will perform. This is what makes threads like this rank on "For you" page.