Don't forget that BTC has other uses than being a currency. It is a store of value and an indestructible ledger capable of storing and transferring ownership rights without counter party risks!
Might be that we will see an alt-coin stepping in to fulfill the role of currency for daily transactions, with BTC acting as the main referent of value and a store of said value. Or BTC could evolve.
Right, or paired cryptos that works off the blockchain by private merchants, interface at the junction and balance the books every 8 hours (the whole fucking world's books). Not to mention the ledger is programmable to receive instructions and payouts, the addresses can be modified to further show unique data... it goes on and on.