\
There is nothing backing the dollar, and there hasn't been anything for 40 years now. Duration mismatch is a bit of a problem, but not necessarily a big one. And money really does come out of thin air when a bank lends. No big deal, that's the system we have, not the end of the world.
Not the end of the world, but certainly the end of any currency that operates on that principle. Which is good for bitcoin, in the long run.