I think this benefit is currently overshadowed by the problems that 1. It costs too much to convert to and from fiat currency, and 2. The bitcoin itself is too volatile in it's exchange rate. But if the currency ever stabilizes and is widely adopted, then fees will lower, and there will be less of a need to convert it to other currencies so a person could just keep so much of their net worth in bitcoins because it's simply economically advantagous and convenient.