> Also that there's almost no reason to want to make truly anonymous purchases.

That's just silly. You can certainly think of things people have a legal right to do that they still wouldn't want any record of. If you're paying for an abortion it's perfectly reasonable to want the payment to be truly anonymous. The same goes for other types of medical treatment, any purchases of an embarrassing nature, donations to politically charged organizations like Planned Parenthood, charity by people who believe altruism is only satisfied when the donation absolutely cannot be attributed, etc. There is also the simple metadata concern that giving anyone a record of everything ever purchased by you (and everyone else) could be used against you or for evil purposes generally.

The ability to make anonymous payments has been the norm since money has existed. Cash is anonymous. It's only the last few decades with the rise of electronic payments that tracking them all has even been possible, and there is no law of the universe that says we have to accept the loss of privacy.