And can you imagine the complete end of cryptocurrencies? How would it look like? Do you think that the price of all crypto around 0,000001 $ is the end of this? Even with that value you can earn good money and it could turn up again. So yes, crypto will last forever, even with veery little value.
There are good and bad cryptocurrency in the market. By that I mean that the coins with good potential will stay for long and this is something that will keep on moving to generation after generation but those with impotent projects wont.
Also, I think that the future world would be laden with the blockchain tech and the coins based on this tech would prevail as long as the technology would exist.