>Looking at the problems Twitter has, why does anyone think Musk can even solve one?

Transparency about moderation is the easiest to fix. All everyone wants out of Twitter is to know why posts are moderated, promoted, shadow-banned, etc. It doesn't have to be super specific, in terms of moderation, but giving everyone an overall sense of how and why things are moderated the way they are, would help to restore a sense of fairness.

If he does well with Twitter in that regard, all the other platforms aren't hard to replicate if you've got the servers and money.

OR

He loses most of his wealth selling off stock to try to do this, and we learn the difference between paper and real wealth.