1. Tank the price, thus freeing up energy and advanced manufactured goods (which are in shortages right now) for proper productive use.
2. Significantly lessen the instances of Ransomware, since companies will have no legal mechanism to actually pay.
Whether the coins continue to exist informally and are traded in some kind of primitive barter system is irrelevant.
And alcohol for obvious reasons.
Will the same people asking to ban cryptocurrencies be content with it or will they move towards banning other unapproved energy consumption activities?
That sounds backwards. I'd rather have hospitals and companies learn some hard lesson in cybersecurity through the threat of cryptocurrency-enabled ransomware than banning a medium of exchange altogether. Finally people are starting to care about backups and best practices.
next time you think a ban is a good thing, imagine I would ban something you do. It doesn’t even have to be something essential. Maybe I ban a hobby of yours. How does that feel?