There's lots of things that an order of magnitude more folks do that harm the environment than DeFi/cryptocurrency/shitcoin gambling. I'd love to revisit the environmental impacts of cryptocurrency after we've moved to electric cars, decreased car usage, decreased HVAC waste, made our toilets/sinks/showers more efficient, made our factories run on hydrogen instead of coal, and clean up shipping emissions. Once we're even halfway down that list, then I think we're ready to tackle the environmental question of cryptocurrency.
> What is lost if DeFi were more heavily regulated or outlawed? What is lost if shipping were more more heavily regulated / outlawed?
Getting people to agree on "low-hanging fruit" is very difficult. Even on here you'll see people that are fine with using energy on crypto. It'll be an even taller order convincing folks that shipping should be outlawed or tightly restricted, especially folks living in rural car-dominated areas of Anglo countries. Then you'll have to mount a new fight to convince people to heavily restrict the bath and restrict shower usage. Oh and keeping your lights on all night. Then start a campaign to restrict running the AC. There will undoubtedly be folks who'll try specifically to find holes in restrictions as well, such as buying a propane stove on areas where gas stoves are banned, then you'll need to amend all of these restrictions and burn ever more political capital.
Much simpler to tax energy based on emissions. If that means PoW crypto will never be profitable, then they can pound sand. That way you also won't have lobby groups grandfather weird exceptions on restrictions to preserve their precious market.
