[latchkey]

The obvious solution is to make everything digital, but that impacts people who aren't digital. Never mind the anonymity aspect.

The other solution could be to get rid of cents all together.

This is what Vietnam has done and it is fantastic not having to deal with small metal change. Although, this created a new problem, they need to lose a few 0's. Being a dong millionaire (largest bill is 500k) means you've got about $45 in your pocket. Heh.

[neverartful]

The anonymity aspect is a huge deal.

[latchkey]

I wasn't discounting it being a huge deal, which is why I mentioned it. But we don't need metal change for that when we can use 'paper' bills (airquotes because in Vietnam they use plastic bills).

[RandomBacon]

There's Monero, but even Bitcoin (which has a 5 year headstart and is not anonymous) is barely supported.

Though I think I would still prefer physical cash over digital cash even if it was just as ubiquitous.