The tendency for cryptos to become easier and easier to use, making it increasingly wide spread(and more stabel) will make a ban on them just as effective as the drug ban. The difference is that people willing to use currency is effectively EVERYONE, unlike the number of people who want to use drugs, but despite that, anyone who wants access to drugs, has it. Given that, the failure in enforcing the ban on cryptos will be even more pathetic.
A ban would initially be actually in effect in large established business, but as the market is always reinventing itself, new, smaller, non-regulated business that deal with cryptos(despite the ban) would gradually and increasingly gain competitiveness. This is in fact another benefit of cryptos, they would serve as a way to get around stupid and protectionist regulations that only benefit the already established business. And again, an effect such as this will be so widepread, that enforcing regulations would be impossible.
In face of this, regulators will be forced to do what they did with uber: bend over and back off.
This is what in the end will force the bigger companies to join in: the need to stay competitive.
These changes won't happen overnight, but at least they will be the way it is supposed to be in a descentralized/free market: from the bottom to the upper part of the economy, because if it is the other way around, things would only get worse.
In a nutshell, once the control freaks lose their ability to control(which was guaranteed essentialy through the monopoly of money), their incompetence will be their death sentence.