In 1913 when the income tax began there was no such thing as the standard deduction. That didn't come along until 1944.
The original income tax was a class tax, a tax on the wealthy, just as was the corporate tax instituted in 1909. From the beginning it came with a personal exemption of $3,000 and if you were married $4,000. Dependent exemptions didn't begin to be added until 1917, starting at $200.
Guess what the personal exemption of $4,000 would be in 2016, adjusted for inflation? $100,000. Times all the individual wage earners in America in 2016 $16.3 trillion would be exempt from taxation. In the third quarter of 2017, personal income in the United States wasn't even $16.5 trillion.
In other words, the original personal exemptions of the tax code adjusted for inflation would exempt all current personal income from taxation, except for maybe $200 billion.
As far as I'm concerned, the government can have that.
Now that's what I call a tax reform.