USD fluctuates wildly from my position in the GBP currency zone. But you don't get out of it - for the same reason you don't feel the 18.5 miles per second you'

USD fluctuates wildly from my position in the GBP currency zone. But you don't get out of it - for the same reason you don't feel the 18.5 miles per second you're travelling through space. BTC isn't taken as a currency because you can't live in its zone. Everybody swaps it into the currency of the zone they are living in - unless they are speculating. You use the currency of the zone you are living in because everything you need is priced in that currency, and everything is priced in that currency because there is a strong taxation authority that demands payment in that currency.