Conjecture

So Elon Musk spouted off about buying Twitter, probably while drunk or high.

Then didn't really want to and it went to court and he was forced to follow through.

So to pay the piper for shooting his mouth off, he goes to his good buddy Salman bin Abdulaziz Al Saud, King of Saudi Arabia, and borrows I believe a few billion dollars from Saudi Arabia, though I'm not currently coming up with a specific figure.

Then Elon Musk becomes defacto an important person in the US government from hobknobbing with his buddy Donald Trump.

While they both likely have nasty predilections in common, that's probably NOT sufficient for Donald Trump to appoint him to a government position of power while cosplaying POTUS, a position he rightfully stole to reference some witty movie line.

Most likely, Donald Trump wanted Elon Musk to help strengthen his relationship to Saudi Arabia. But after borrowing a huge sum of money from Saudi Arabia to buy Twitter at gun point, Elon Musk then tanked the value of Twitter and it lost something like eighty percent of its value.

I suspect he was overextended before that and really couldn't afford that loan before he ruined the company he bought with that money. So he may be in arrears on that loan and unable to catch up.

Which might explain the public falling out Donald Trump and Elon Musk had: Donald Trump may have had an epiphany that Elon Musk wasn't really useful to him in that regard. In fact, he may have suddenly looked like a liability.

If you like conspiracy theories, you could look into this. Maybe check if his visits to Saudi Arabia suddenly fell off a cliff after buying Twitter less than four years ago as potentially relatively easily checked public information.