I would prefer it if I could pay in cash fractionally, without having to give or get slips of paper, file that paper in a portable filing cabinet in my pocket, keep up with how many slips of paper of what denominations I have in my filing cabinet, and periodically run out of slips of paper just at a time when I most need them.

The worst is giving somebody one slip of paper and receiving in return multiple slips of paper and several bits of metal. Then I need to file the bits of metal too and remember how much in my pocket they add up to, or, more likely, keep them at home and never use them for anything.