Buying the government (if doing so was even possible) means they need to furnish it’s debts.
Even if a company was willing to to undertake such a burden, nobody makes more money than the government, it just doesn’t have much reason to hold onto any of the cash it collects.
Besides, they can just print more.
Edit: that’s not to say it isn’t hilarious
I wonder how much the Federal Reserve printer costs.
Asking for a friend that wants to make an infinite % return on investment.