The solution here is simple and it’s the same as every other freemium service: milk the whales and serve ads to the plebs. Ideas specific to Twitter:
animated avatars
post borders
badges
early access to new features
ad few tiers
Iterate on that and you’ll reach profitability, assuming you start with a healthy userbase. The trick is to make them noticeable enough to stroke narcissists’ egos, but not so distracting that it turns into a clown show.
Basically, something like Reddit Gold, but broken up into multiple pieces. Those who don’t care can ignore it, and those who do can pay out of nose for it.
That Musk doesn’t see that just shows how clueless he is. He tried that with the blue check mark or whatever, but he completely changed the meaning behind it, which breaks a huge rule in UX, which is to not drastically change the meaning of existing functionality.