I see a few benefits, but nothing on the order of the full potential of crypto.

1. Your FacebookCoin value is a collection of the world's currency value and not tied to a single goverment currency. It's more likely that {Single Fiat Currency} experiences hyperinflation than {Collection of Fiat Currencies} thus some of your risk is mitigated. Most individuals hold the majority of their wealth in a single currency, or in assets that are sold for a single currency (NYSE transactions are completed in USD, same with US based real-estate.)

2. Transaction fees can potentially be lower than incumbents. This is probably going to be especially true with person-to-person international transfers and could big a huge win for third world startups dealing in digital services.

3. The barrier to entry will, in all likelihood, be significantly lower than traditional banks. I've known people with a credit score so low they couldn't open a bank account. I've meet people with anxiety of using a debt card because of over withdrawal fees.