Your point in non-nonsensical. If T-Bills are equal to cash, then the government doesn't need to sell them, they'd just use them like cash. Yes, they are very

Your point in non-nonsensical. If T-Bills are equal to cash, then the government doesn't need to sell them, they'd just use them like cash. Yes, they are very liquid, but they are not cash. Even if they are only cash-equivalent in certain situations, they'd be increasing the money supply by freeing up the cash that would otherwise be used in it's place. "The government can borrow money, use it to repurchase government-issued cash equivalents" Yes, this is what's being done today. But it does not resolve the government's debt, it just changes who they owe it to and when plus interest. So the net effect is an increase in debt. This process is only sustainable for as long as people are willing to lend the government money.