Tl,dr: Musk is irratic and has no plan, per a journalist who has covered him for five years.
His solution was also to cut down their usage, which is basically the opposite of what you want your users to do when you’re running a social media network.
Fewer users means that there are fewer people watching the ads, which means less income. It also makes it harder to justify subscribing to their premium service if you’re on the site less.