If you mean by "cryptocurrency": pay through blockchain, without bank or P2P transactions. I expect this technology to dominate the future.
Perhaps in the future lose one of its most essential features *decentralization*, but it is an excellent way to conduct transactions between countries "low fees."
As for cryptos in its current form, most of these currencies will disappear over time "we have more than 1700 coins".
Staying may be for the top 10 currencies, or new currencies that develop a qualitative evolution "as Ether did before."
Of the price, the use of technology will lead to higher rates, although I expect the future to be stablecoins "run by governments."