That’s just dumb things from the last 20 years. I think you may be suffering from a fairly severe case of survivorship bias.
(If you’re willing to go back _30_ years, well, then you’re getting into the previous AI bubble. We all love expert systems, right?)
On the other hand, normal cryptocurrencies continue to exist because their proponents find them useful, even if many others are critical of their existence.
Technology lives and dies by the value it provides, and both proponents and detractors are generally ill-prepared to determine such value.
The orignal topic was "not once blah blah...". I don't have to entertain you further, and won't.
Baseline assumption: HN is full of people who assume that the current fad is the future. It is kind of ground zero for that. My HN account is about 20 years old and the zeitgeist has been right like once.
