Unless Bitcoin has a fundamental evolution, it cannot be a replacement for fiat currency.
I'm super excited about the crypto currency space but I firmly believe we're in the "Diamond Rio" phase of a new technology and not yet to the "iPhone" and "Android" phases.
Bitcoin does not need to, will probably not, and was never intended to completely replace fiat currency. As a cryptocurrency aficionado I think it can achieve great success and high adoption while coexisting with fiat currency.
I don't need to pay my cup of coffee in bitcoins, but Bitcoin is very useful for plenty of other use cases.
I find the claim of being able to cheaply and quickly transfer large amounts of money to be comical. The argument breaks down to, traditional transfer methods take too long, so let’s add two layers of traditional transfer methods on top of a bitcoin transfer. Then we just ignore the bid/ask spread and the transfer time on either side.
You are not thinking outside of the box: the advantages of Bitcoin multiply when you stay in bitcoins without converting to/from fiat currency.
For example my brother in France owns some bitcoins. One day he sent me, who live in the US, some bitcoins. I was able to spend them instantly (~10 minutes) on NewEgg to buy computer hardware. None of us had to convert to/from fiat. The fees were small and the transfer was incredibly fast compared to a regular bank wire.
I'm super excited about the crypto currency space but I firmly believe we're in the "Diamond Rio" phase of a new technology and not yet to the "iPhone" and "Android" phases.