It doesn't actually "fail", at least not from the perspective of the makers of the system. The collapse is hardcoded into the system, so what looks like a flaw to us is actually a feature. What we call "Crisis" or "Crash", the central banks call "Christmas", because that's when they get their presents - we call them "collaterals".
That game might change in the foreseeable future, though, because the Internet now is coming for banking.
That game might change in the foreseeable future, though, because the Internet now is coming for banking.