There's flat tax proposals and implementations at every level of the economy in different countries, not all of them have to do with income tax. E.g. the case

There's flat tax proposals and implementations at every level of the economy in different countries, not all of them have to do with income tax. E.g. the case of the warm and cold chicken being taxed at different rates, as described in the linked Economist article. It's common in places with such a distinction in the tax code for some stores to sell packaged cold food clearly intended to be eaten on the go, and then to conveniently offer a customer-operated microwave on-site partly as a way to avoid paying a tax that distinguishes between food sold as groceries v.s. take-away food. I'm not advocating for flat taxes, but it is correct to say that such proposals in general do away with such emergent absurdities, and decrease the need for government bureaucracy.