Sales taxes are regressive. It's the rich and upper classes that stand to gain the most by the abolition of income taxes. They don't consume enough to drive up huge sales tax bills. In terms of positive generation, mostly they accumulate income and asset gains. Overwhelmingly they don't spend their wealth on buying Ferraris and mansions. In the US the top 10% pay 71% of all income taxes (while taking home 30% of the income). Their consumption is not high enough to offset if you switch to a sales tax system. It would do something beyond brutalizing the bottom 3/4 of people; it would destitute the majority of workers in the country if you attempted it and were serious about trying to bring in enough revenue to offset the loss of the income tax.
The US has a very progressive income taxation system, far more so than most of Europe (including all of Scandinavia). The US middle class and below pay exceptionally low income taxes, the burden is overwhelmingly carried by the higher income brackets already.