No, cryptocurrencies will not go down for the same reason or as the dot-com bubble. The latter was, in actuality, a subprime venture capital bubble (as I explain in The State of Venture Capital). We still suffer the debilitating consequences of quite a different problem than the flawed concept of cryptocurrencies.
Cryptocurrencies will implode because they are not correlated to the discriminatory trust in tangible asset values aiming to serve humanity and inflate in value only by incremental indiscriminate participation. Kind of like suggesting a religion becomes truer when you can find more believers for it. An evolutionary fallacy indeed.
Cryptocurrencies thrive on the innate susceptibility of the human brain to hallucinations. Much of it is induced by the grave depravity of reason stemming from confounding consequences and causes I write about so often.
When cryptocurrencies fail depends on many factors, too complicated to predict with high accuracy and not helped by the unpredictability of the innocence and a seemingly endless supply of greater-fools.