@lxo that is precisely my point :) The banks have already solved the federation problem for you. You then have to pick the one you like the best. #mastodon still has no "banks". We are still interacting with very "raw" services.
Another way to see it is on how the web got started. The protocols existed and the nodes could talk to each other. But it wasn't until AOL "packaged" it that we started seeing massive adoption of the network.