If I was a politician and in charge, I'd ban both in a heartbeat. Even though banning "cash" would be practically impossible, because people would then just replace it with barter, or favors or bottle caps.

But if it were to come to that, I'd replace it with some sort of digital currency that is "private" but accessible to the government within rules and reason of course.

Here is one prominent Bitcoin opponent arguing that people shouldn't have the right to exchange money in private:

https://twitter.com/smdiehl/status/1381152231836254211

It hasn't necessarily been out front-and-center in the mainstream media, but it's definitely something getting talked about in mainstream financial circles routinely. Here's a bit of a partisan source from a quick google search, but it's got a lot of links and citations you can follow up on and I believe it is basically correct in its facts, even if you disagree with the conclusions drawn from them: https://www.newswars.com/cashless-society-democrats-propose-...

It's up to the "trial balloon floated in Congress" point. The trial balloon has so far always been shot down, but it's really only a matter of time. If the government could just push a button and have access to literally every single transaction that occurs, they would certainly do it. They wouldn't even blink.

Also, I want to say, I'm just linking one example. You can follow up with search terms similar to the ones used in that article, and probably find even more mainstream sources discussing it. It's a topic in the air in financial circles.

Edit: Bit more searching, here you go with something much more mainstream, Forbes: https://www.forbes.com/sites/advisor/2020/10/22/the-pandemic...

And again, my main point here is that it is a topic of conversation, not making any particular claims about where we are currently.