He literally has main character syndrome so extreme that he must be the one to save humanity and bring us to mars. Nobody else can be allowed to save humanity, it can only be him.
Why would he hide behind a burner account? The people need to know his opinions so he can lead us to our glorious future. Do you not know how dank his memes are, pleb? Are you not wowed and amazed and impressed by his knowledge of everything, including his suggestions how to quickly rebuild a bridge? Elon and his beautiful mind have thoughts, and until he can stick a Neurolink chip into your brain so that he can deliver them straight to your head whenever he thinks they're important enough (everything will always be important enough), he needs to go to the Twitter machine to share it with the world.
Like, homeboy genuinely, honest-to-god thinks he's the main character, and surrounds himself with people who enable that.
Otherwise yes, it seems so fucking obvious to the rest of us to just shut the fuck up and enjoy our billions and figuring out what terrible problems we could just dump money on to try to fix it. Or just buy/build a bunch of artificial islands because we're detached from reality and have nothing "better" to spend our money on.