“Money is a matter of functions four: a medium, a measure, a standard, a store.”
Most of the talk was structured around discussing these functions. Medium is pretty obvious: the dollar is the universal medium of exchange. It is basically frictionless, trading at zero spread (with perhaps a fee to wire dollars internationally). Bitcoin claims to be a medium, but it’s slow, can be expensive due to limitations of the blockchain. And as later confirmed by bitcoin proponents, bitcoin’s bid-ask spread is wide and can widen unpredictably for large orders. Like $5,000.
Even in cases where bitcoin is a medium, there is a third-party currency exchange broker who finds a fourth party who wants to buy bitcoin. The merchant gets the dollars he really wants, the customer pays in bitcoin, and the fourth party buys the bitcoin and provides dollars to the merchant. All for a fee charged by the broker.