The way I see it is fewer and fewer people pay with cash nowadays, and when they are paying cash fewer and fewer of them are doing the take and leave pennies thing.
Words on the internet is that it cost a lot of money handling cash nowadays due to robberies and accounting, unless it is a tip based business I do not see why people want to do that, and even if it is a tip based business they would rather you tip the changes instead of rounding to dollar or quarters. We start seeing places targeting middle class and above, and they don't take cash (i.e. Sweet Green), only card and maybe Apple Pay, online payment, etc. I think this will be a trend that's long overdue.
Whenever I go to Safeway I dump the pennies in the self checkout before I run my credit card, many vending machines don't even take them anymore so might as well clear things out.