An argument that someone could make, although maybe it's a bit logically suspect, is that Twitter is losing money for every user, and using Twitter is costing Musk more money than it's generating for him.
If I were acting in order to maximize losses, I think the latter would be more substantial. It also has the added benefit of not being exposed to the musings of Musk himself and the fascist crowd his reign has attracted to Twitter.
(I feel like a hipster on this discussion, I stopped using Twitter way back in 2016 before it was cool when I saw it's retweet/quote-tweet tools used to launder targeted misinformation from its terrible personalized ad networks all being abused as a cynical political tool. It was terrible before Musk got involved. "X" is a lot worse, but the downhill started years before, according to this early Twitter adopter.)