I’ve never been on Twitter, but Musk said in interviews that he uses the blue check to show that an actual person posted. Musk has said thatPrior to him buying Twitter, during Election time and during Covid that almost half of the postings were Bots, and not by an actual human. Made to look like far more posters had an opinion than actually did. He did this to get actual numbers and force the fakers off his product.