What do you think of the Fair Tax Act?
The FairTax Act is a US bill that calls for the abolition of all federal taxes (including income tax), levies and (social) security contributions and instead the introduction of a uniform, national sales tax as the only federal tax.
https://de.wikipedia.org/wiki/FairTax_Act
I think such a tax system is good because it would be fairer and less complicated than the existing system.
How can it be better or more equitable if the avoidance strategy or even the background would be between 15 and 30%?
From your source
It sounds very good.
But the current problem that part-income millionaires do not pay taxes would not really be changed.
Ok if someone lives in the USA he will always pay a little tax just by the consumer tax (in the case of turnover tax) but if someone has, for example, a net income of one million US dollars and let us say 100,000 in the year for everything possible (which is already an extreme standard of living) would be 900,000 incomes in the year absolutely tax-free.
And with billionaires, it looks much worse.
In the end, it remains the mass of taxes paying the problems have to pay to not be able to afford it loose.
A mere consumption or turnover tax, of course, makes smaller income more disproportionately burdensome.
Those who have to spend their entire income will be fully burdened, with surpluses rising untaxed.
That would be very UNSOZIAL