I can remember when it was first floated to have a GST (VAT) in Australia. The Howard Govt was suggesting, if I remember correctly, 10% on everything. This was changed to 10% only on certain types of items. However, before the GST came into effect, most of the govt's top economic advisors were suggesting a flat 20% GST on all products, even imported goods, and ZERO personal income tax, which meant that people had more of their wages to spend. Their argument was that the govt would raise more tax this way. They even used Kerry Packer as an example. Packer purchased his private jet/s overseas and flew them into Oz, no tax paid on the planes. The economists plan, if implemented, meant Packer would have to pay 20% GST on a plane worth millions of dollars. Howard liked the idea but the Treasurer Peter Costello somehow managed to convince parliament that this wouldn't work.
The economists did get it right because their GST formula actually meant that the rich would end up paying their fair share of tax as they would be purchasing high value brand name items, thus more tax paid by them, and with this GST formula it guaranteed that they paid their fair share of tax. Of course history shows that this didn't happen and the middle & low income earners still pay the most personal income tax as they don't have the loopholes & tax havens that the rich do.
Govt's, regardless of which country, will always structure their tax rules to favour the wealthy.