I doubt it when he used the word 'all'. In as much as we predicts and wish that cryptocurrency will be widely used, there are still some companies which will still be reluctant to accommodate it. Nevertheless, this will not stop cryptocurrency especially bitcoin from been the most valued asset in years to come. It value and price will be so high that no rejection from anywhere can stop it.
I think they will rule the market in five years.They are getting very famous in the market as they are very simple to use and are a great opportunity to earn money and a lot of profit rate.Taxes are also not implied on them so the person receives full payments.Cryptocurrencies are also used as assets as people hold them for future price rise.I think these cryptocurrencies can become legal in some nations.People like new technologies so they are accepting these cryptos.