That would tend to encourage raising tariffs. Which is, generally, bad for business (and gets very complicated in the context of trade treaties and the WTO).

So what would happen is that businesses fight for lower tariffs, and are the check on incremental government growth.

Instead with the IRS, the taxes keep on going up and up and the little guy can't do anything meaningful to fight the trend.

(hmmm... looking at where we are now, maybe the businesses won in their battle to lower tariffs - shifting them to individuals)

Income taxes are a tariff on labor.

A tariff is very literally defined as a tax on imported goods, so neither income taxes nor payroll taxes are tariffs on labor.

They are simply taxes on labor.

> Income taxes are a tariff on labor.

Payroll taxes are a tariff on labor, income taxes include non-labor (but “long-term” capital only at a favored rate) income, so aren't exactly a tariff on labor, though they also aren't neutral between sources of income.