I disagree, privacy without anonymity isn't really privacy at all, it's little more than trusting that the other party is going to be nice to you (which backfires extremely often, eg porn site or dating site payments are "private" until they mess up their security and everything is out in the open).

"True" privacy requires anonymity and the fact that existing systems have been terrible on that end isn't much justification for banning systems that do have proper privacy.

First, I do use cash..kind of weird to act like cash is an edge case. Second, how is your information private if an intermediary or intermediaries knows what you bought, when, and for how much? In some hypothetical world where PayPal, Mastercard, or Visa didn't immediately turn around a blab to everyone in sight what I just did, fine, but that's not remotely the world we live in.