In the good old regulated economy, individual depositors of a bank are protected by the FDIC (up to a certain level), and have no reason to engage in a bank run

In the good old regulated economy, individual depositors of a bank are protected by the FDIC (up to a certain level), and have no reason to engage in a bank run. Now, if all those individual depositors instead give their money to some unregulated entity (USDC), and that unregulated entity gives $50 bn to a bank, and then one day turns around and says to the bank "hey, I'd like my $50 bn back", then the bank might not have that much at hand right now. And since the unregulated entity is not covered by the FDIC, individual investors might have an incentive to engage in a bank run.