Technology

You can exchange it for goods and services in the same way as the dollar. Which is the goal of it in the first place. Disregarding the cost for the sake of this point

But you can't disregard the cost. No big box retailer is going to start accepting BTC transactions at the point of sale. It takes too long, and is too resource intensive. So you're essentially limited to secondary markets or person-to-person transactions where seconds in processing the transaction don't count. Not to mention the volatility of the exchange rate. A business or a government aren't going to accept that the currency they accepted today could potentially be worth half its value tomorrow. Without some sort of major catastrophic world event, something like that isn't going to happen to the dollar. That kind of shit destabilizes entire economies and nations.

There's also the issue of reputation. Regardless of validity, cryptocurrency is seen as something used for criminal activity. If your local city government said they'd start accepting BTC for your water bill or trash bill, the majority of average folk are going to think "that stuff people buy drugs with on the Internet?"

BTC has never been and will never be viable as a mass market currency system.