Twitter is a terrible technical foundation to build a "super app" upon. Indeed it makes no business sense at all because Apple and Google already have a super app called a phone and an operating system. Plus, if they wanted to create a monolithic do-everything app, they could do it infinitely better than Elon Musk. Why would they let someone hijack their operating system to become all things to all people? Make no mistake if Apple wanted to, they could make a Facebook and Twitter killer and sell twice as many phones while protecting privacy and managing the whole thing in a professional, tight way to where no one would need Twitter at all. All they need is a reason.
On top of this, if they really are making a killer EV as rumored, they would definitely mess with the competition in ways he has yet to imagine. And they have WAY more money than he does.
This is a case where the fantasy is very far removed from the reality.