Weed in the US is still a federal crime. They can stop you at the border for posting you doing bong hits on your social media. yep. They may not have been publicizing but they can.
There seems to be State supported reasons for the base numbers on crypto. China's recent bizarre statements on it appear to be a hedge towards freedom from the greenback and the international banking system.
I agree with your premise that the more things are 'legalised' to whatever extent, it changes how they're sold - just ask the cigarette companies that own patents and registered trademarks for weed based products. I'm not sure the legalities however are ready for prime time and it's still grey market.
The proposition that the darknet is going clear does not logically follow on from one to the other.
I can see the argument and accept that as it moves legal status it may change 'domains' (societal rather than ICANN
)
There are other reasons for the existence of the dark web, not just for things society doesn't approve of such as 'substance' or 'awful behaviors', but in terms of social control and political and informational control.
As places like NK embrace crypto and moved through 'secondary' markets there seems to be a baseline support for it, because it allows them to circumvent the complete control systems imposed from western sources.
When Russia stifles the net, BOOO. When the US does it for our 'safety' OOOH'.
Both cases create a need for free information flow beyond State or Capital control.
I am firmly in the camp of 'genie-out-of-the-bottle' and I think the informational changes have yet to be fully manifest. Woe be those who predict the future