I won't be so sure.
Remember when global trade went down the tube, government will impose capital control. Cryptocurrencies will the the first on the list.
Andreas Antonopoulos said in a video that it will not be so easy to regulate cryptocurrencies because then it will be like what happened with the shutting down of Napster and services like that and BitTorrent was developed. Another problem he mentioned was that if for example Russia will make bitcoin illegal, then other much more stealthy cryptocurrencies will be used. Something like that.
What I think could happen is that governments will issue their own regulated cryptocurrencies! Those could have unfair advantage of being supported by regulations. But even then, they can't make it too unfair, or people will use unregulated coins instead. On the other hand, if a global officially regulated cryptocurrency would be developed, and if it was fair enough it would be good. To make it fair they would have to allow bitcoin and the altcoins to compete with the official coins.