Reminder: being able to "pay for stuff using Bitcoin" doesn't scale in the physical world until you can actually own land using Bitcoin.
As long as the authorities need dollar treasury contributions for letting anyone produce the food you eat, they can print all the dollars they want and still force you to use them. You can "buy" a house with Bitcoin, but even if the seller doesn't convert the money to dollars, you'll still have to convert whatever amount the tax collectors demand.
A video game company can offer to let you download a game in return for Bitcoin that they just keep, but if a farmer offers you food in the real world for Bitcoin, how will they keep increasing that food supply without the Bitcoin being converted into dollars?