Agreed, we need larger denomination notes to keep cash usable. Despite decades of inflation the largest notes printed are $100 and it has been that way since 1969. Even $500 note doesn't get us back to buying power parity (it's about $800 btw).

I've been to places that only accept credit card and it's infuriating as a consumer, and confusing given my relationship to small businesses. Consumers expect the same price regardless of their method, but the card fees are painful. Especially given our (former) payment partner (but really the CC companies) are doing everything they can to take more money[0].

[0]: https://news.ycombinator.com/item?id=34996006

Cash is not king. If you're in the US and you're paying without using a credit card you're effectively losing thousands of dollars more than those that do. You can disagree that credit cards should have the ability to pay users cash back or offer travel rewards, but you are losing money by using cash.