Yeah the out is that you can buy goods and services with it. I could've paid for my VPN (Private Internet Access) with Bitcoin, Overstock takes Bitcoin, those ATMs exist.
If everyone suddenly wanted to cash out, it would crash and very few people would get money for it, but that's also what separates it from a Ponzi scheme, the fact that I don't need to transform it to USD to spend it. There was a hard push by Bitcoin enthusiasts to get some places to accept it directly for exactly that reason.