Nobody knows.
And anyone who tells you they do is just cheering on their own football team like a one-eyed fan.
Some plausible outcomes if I talk about BTC specifically.
We may be in the early stages of one of the great speculative bubbles in history and its going to $100,000 plus.
We may be in the late stages of one of the great speculative bubbles in history and it will lose 70% of value inside a year.
Bitcoin may eventually be supplanted by a better, more useable cryptocurrency (highly likely). Billions of dollars being spent right now on exactly that.
Governments may crack down hard on exchanges (or tax them heavily), reducing the utility of decentralised currencies. Not much use having all your speculative gains in magic beans if you cant get them out.
The USA could plausibly say that Bitcoin is being used to fund terrorism and crack down hard on it.
There are probably hundreds of other similar scenarios I have not considered.
NOBODY, and I mean NOBODY knows.