And worst of all, the momey you pay isn't tied to your license plate. If you overpay, someone else can park for free!!

The other problem, in the US at least, is that cash is very low value (inflation), and dollar coins never caught on. I'm not trying to carry around $6 in quarters to park for 2 hours. And that's a pretty inexpensive parking spot.

...are you implying that digital money is worth more than digital?

because I doubt anyone who spends cash regularly is holding much of it long enough to lose value to the digital ones in their checking account.

No, they're implying that you need a lot of coins to pay for parking.

If you need $6 to pay for parking, and the largest commonly available coin is a quarter, that means you need 24 coins to pay. If the value of currency was such that the parking only costed $3, or if dollar coins were more common, you'd need less coins to pay.

For context, in the Eurozone the most valuable coin is 2 EUR, or about 2.30 USD.

And maintain them, which I suspect costs even more. Parking meters do fiddly work, out in all weather, where people hate them and do all kinds of vandalism.

It doesn't surprise me that they want to make hardware maintenance your problem.