Well it depends IMO. Once trust is lost, it could go very quick. However, I do think fiat will be around for a couple of centuries. Especially the dollar, which will be the last one standing. 

CarlBMenger

bitcoin

How money evolves

Thanks for sharing the article.

I think bitcoiners underestimate how long it takes for fiat to collapse. Sure, Venezuela, Zimbabwe and Argentina all collapsed but those were the shitcoins of the fiat world. Bitcoin should be compared only to the dollar in that respect.

It might take centuries for the dollar to collapse.