The fact that bitcoin exists without borders and isn't even physical means that it's a lot more convenient for citizens in remote, economically suffering countries can have access to the same currency as everyone else easily. That's a huge advantage. Also, with an independent currency like bitcoin, you don't need to deal with a depreciating or collapsing local currency.
Eventually, this could be the argument that kills alot of anti-Bitcoin sentiment; there are more volatile fiat currencies in the world than there are stable ones. In years gone by, USD was the desired money when your national currency got too hot to handle. It's almost self-fulfilling that this demand will slowly change to Bitcoin over time, as people only want USD because it's falling the least. Why choose something that falls when you've suddenly got the option to use a currency that's rising in value?
Exactly. People criticize bitcoin for being "too volatile", while fiat currencies are essentially consistently losing value. Bitcoin, even though it may be a little volatile in the short term (which has actually gotten a lot better as markets matured over the years) holds its value over the long term as it has a hard coded limit on the supply and a scheduled emission rate.
Thus, the argument that bitcoin can't be successful because it's volatile doesn't make sense - show them the purchasing power of any fiat, Bolivars, Zimbabwe dollars, USD even over time.
