Elon Musk is already one of the people who thinks about the good for our world and we all know what he does, so you know cryptocurrency promises us better future and considering Musk always thinks the best for world, so news did not suprise me.
Musk has undoubtedly achieved a lot in his life, I don't think we were waiting for him to make that statement to consider it as a fact.
Whiles't everything takes time and just like a stock the slow it goes up creating resistances the safer and foreseeable it becomes in the long run, Practically i don't think bitcoin, ripple or any other crypto would work for the cashless future because of the power it's consuming to mine those blocks.
However, XRP is a good option but do you think the government would use a 3rd party crypto just because of the hype?
I'm 80% certain that the future is going to be cashless, but the cashless currency you use would be of government.