I think it would be wise to have both gold and cryptocurrencies.
Gold for example is destined to go up, because central banks, especially the Fed have to continue printing money which will create inflation. There´s no way the the gold price can be manipulated down in such a scenario.
And all the eastern countries (China, Russia etc) are hoarding gold to protect themselves against inflation. They wouldn´t do it, if it is a useless asset.