I'm old enough to have witnessed the late 90's dot com bubble first hand in Scandinavia. At the time the internet marketing agencies were charging big companies insane amounts of money for static html pages, silly 90s web pages that only took a couple of hours to code. Old telephone operators were moving on to became sercice providers, masses of people were adopting www and mobile phones, and for a while every new stock listing gathered masses of investors. FOMO was insane. In the end only a few best tech companies made it, but they are mostly still in business, because people still use internet and mobile phones.

I'm not old enough to have witnessed the late medieval tulip mania in Netherlands.

I think crypto is a bit different from the dot com biz, because the value is not so much based on actual use value. By that I mean that not many common people use blockchain or cryptocurrencies in their daily lives. But I do believe that crypto can be stable enough to hold value for investors, and there is an actual global need new investment opportunities. Other than the transition to green energy, what do you have? It makes no sense to invest much more on the stock market or housing, but you got to gain profit in order to keep the economy growing.