> Historically that has been true, but couldn't technology help?

No, it's a fundamental structure problem, not a technology (aside from the sense in which an economic system is itself a social technology) problem.

> Like, issuing everyone a smartphone and having them register all demand and make all purchases through it.

From a utility signalling perspective, that's not significantly different in the information it provides than just retaining currency for consumer purchases, which state socialism generally has.