There is a real world cash based economy. A lot of person to person trust exists in that world too. Not everyone is middle class and above, drinking their Starbucks coffees paid for on their credit cards, even in this "first world"... Have you never been to a local market? Stallholders generally much prefer cash, even to the extent of causing the customer inconvenience. Bitcoin is the internet equivalent of this.

I don't actually think it will be of huge benefit to people like you who are happy with their credit cards. What Bitcoin will (and is already doing) is enable new applications and a new internet economy where location and real identity is no longer important.

(In this sense, I suppose I'm kind of agreeing with you, since I don't necessarily think there are any absolutely concrete examples of Bitcoin supplanting CCs. I think Bitcoin's greatest potential is elsewhere in untapped areas.)