Remember, he didn't exactly buy Twitter cash in hand.
The money he used came from all over, only about half of it from selling stock he owned, the rest is banks and foreign interests (a very large one being the Saudi).
His goal was probably genuinely to turn it into a success with his own political views ruling the platform, but to do that, they should've stuck with his usual shtick of him being the PR face of the company while actually competent people do the work and make the decisions. Whatever political shite he spouts on the platform then doesn't matter.
But the other interests wanted Twitter either in the hands of someone they can influence, preferably someone with questionable morals and a similar totalitarian political view, or have it destroyed. For them, either way is perfectly fine.
They got what they wanted and the useful idiot is left to look like a fool.