They could be logged, but unlike blockchain currencies they aren't logged right now which means historical analysis is impossible. And logging isn't inherent to

They could be logged, but unlike blockchain currencies they aren't logged right now which means historical analysis is impossible. And logging isn't inherent to cash. The transaction chain would be broken by anyone who doesn't keep a log. On top of that, the scope of who can see the logs would be limited. I guess the assumption here is that retailers and the like would be compelled to provide that info to the government, but I'd still prefer that over the info going to absolutely anyone who wants it (since "the government" is a subset of "anyone").