>>824833The problem with such a tax alone is that rich people pay a lower
share of their income than poor people.
VAT is also known as GST in Australia, NZ, and some US states. That is, goods and services tax. Poor people spend all their income on goods and services, while rich people have investments, cash on hand unspent, and so on which aren't subject to GST. The cheap counter argument is that this money will one day be spent and subject to GST, but that's not necessarily true: if they were eventually to spend all their income they'd stop being rich and have nothing to pass on to their kids etc.