Sigh ... I get that. Here is what I don't understand:
The illogic that says merchants preferring cash are tax cheats and that all cash tips go unreported*. Both conclusions are prima facie false.
Then the rants about how reprehensible these theoretical sins are. That's mostly what I don't understand. What is the point of this?
Why get upset over something so economically trivial? Really, if you want to get upset about something that is not trivial, worry about the US position of #22 out of 180 countries in the Transparency International corruption index -- even behind Estonia. Or maybe get upset that a majority if Illinois governors seem to move from the mansion to prison? A few shopkeepers and a few servers not reporting 100% of cash income does not even move the needle.
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*BTW, the IRS understands this potential problem and goes to some lengths to ensure that cash tips are reported:
https://www.irs.gov/businesses/small-businesses-self-employed/tip-recordkeeping-and-reporting