See I don't necessarily agree with you there, it all depends what you're trying to achieve. I think in the context of the discussion - an article which says that cryptocurrency is being seen as bullshit by democrats - you just have to make it difficult for normal people to participate in order to kill the current industry, and you can do that by regulating banks rather than individuals. You could make it illegal to market these things, illegal for exchanges to operate and for banks to send money to them, and you'd strangle the majority of it.
Yes, you're right that there would probably be a residual demand for it illicit purchases, gambling, that sort of stuff, but the mainstreaming of it as an investment/speculation vehicle would likely be crushed.
If I can't buy cryptocurrency by credit card or bank transfer then I'm probably not going to try and invest my pension in it, or invest in a high-yield staking account at Celsius, or just buy some BTC at an exchange to speculate on price rises, firstly because my bank would throw up obstacles and secondly because it would be difficult to rehabilitate any gains into the system. Yes, I might want some to buy drugs, but the pseudo-financial industry that's sprung up around this stuff (the FTXs, the 3ACs, the Celsius, Coinbase) wouldn't be able to operate in that sort of environment, and the number of people who are in it to make a buck would be considerably reduced.
So -
> Cryptocurrencies are a second-order desirable in the same way that meeting in private, instead of public, is.
Yes, for transactions where that's important, I can see it still being desirable, until/unless some other means to do this comes along, and you're right, that would likely be a comparatively resilient demand.
But for the current speculative mania, and the large-scale fraud it enables? Less so.
(Frankly if I have to take cash down a back alley to get some bitcoin to buy weed ... I may as well just buy the weed there!)