It should be that way, but it isn't. He has been given the keys to the city and it's inner workings, whether it is legal or not. Sometimes the difference between legal and illegal is whether prosecuted. It is clear, Trump owes him and is repaying, for paying for the trump campaign. It was an election cycle where rank and file, long term Republican donors, simply would not contribute at previous levels, that would sustain an effective nationwide presidential campaign. So, without Elon forking up 64 Plus Percent of the campaign funding, he paid for the victory, and bought the control, he desired.
I too, submit my opinion, giving direct access control to the Federal payment system is beyond the pale. But, with trump pick in DOJ having more loyalty to Trump than the country, it is unlikely any action will be taken. It simply boils down to how far trump allows Elon to go.