> Elon could just go fetch $44bn from a bank to buy Twitter without anything to back it?
Collateral "becomes more important the more perilous the borrower is or might be." It's immaterial to "someone with a century of living expenses."
Elon Musk could probably have borrowed even $100mm unsecured on terms damn close if not identical to that which he could get on a secured loan, ceteris paribus. But Elon is uniquely leveraged. That makes him a more perilous borrower. And $44bn isn't lifestyle borrowing, either.
Nevertheless, he could still probably get a hundred million lent unsecured on terms quite close to his secured rates--there are groups who would do that for relationship building alone.