There are pros and cons to cash and cashless. For most people in a normally functioning modern society cashless is in theory convenient "better": automatic electronic transaction record (for your own use), no making change, quicker, less physical items to carry, etc. The #1 advantage for modern cash users is privacy. Some people don't want to have all of their transactions tracked and mined by others. Not considering privacy, there isn't much cash has over cashless aside from working offline, but again, normally functioning modern society.

My favorite thing about using Apple pay is I don't have to touch anything (most of the time, anyway). I just double tap my watch and hold it near the card reader and that's it.

Having that convenience is super nice right now!

What do you mean? Then you could pay for stuff privately over the internet.

I'm surprised there hasn't been a first amendment case over this -- maybe because of the continued existence of cash as an alternative?

What business is it of the government what books I read?

It's more like the banks and payment companies. Your data is monetizable, so the people who create cashless systems have a strong incentive to make them less private than cash, in order to increase their revenues.

Most payment systems allow the "bank" to make money in various ways. Either you've deposited some money and they get to collect interest on it for the time between then and when you withdraw it (like checking accounts), or they get a percentage of transactions (like credit cards), or the system is one where the tokens expire after a period of time (like gift cards) and some of them go unspent which allows them to keep the money etc.

A system can be private and be funded in any of those ways. The incentive to provide privacy is that it allows them to out-compete other payment systems without privacy, and then they get more deposits/transactions/unclaimed funds.

The primary reason this doesn't exist isn't that companies wouldn't provide it, it's that there are various laws that effectively prohibit transaction processing systems that provide meaningful cryptographic privacy guarantees.

This is where a lot of people had hope for blockchain -- most of those laws apply to the payment processor and it doesn't inherently require any payment processor entity for them to apply to. But with that comes a lot of other disadvantages (limited transaction volume, wasteful energy consumption, lack of a controlling party to provide up-front resources to address early user experience issues), not to mention the speculation-inducing deflationary nonsense, which would have to be overcome before it could expect to become popular with ordinary people.

Enough of those might eventually be addressed enough to make such systems enter common usage, but we would obviously be better off to do something about the laws prohibiting cryptographically private payment processing systems using ordinary payment processors instead of forcing people onto these ugly workarounds for something everybody should have a right to anyway. It's still not any of the government's business what books I read.