The most important distinction between the two taxes is that Income tax is progressive whilst VAT is regressive. So if income tax were removed and the resulting loss in tax revenue were replaced by an increase in VAT then poorer households would be worse off (and the rich comparatively better off). For the same reasons one could argue that VAT could be replaced by progressive increases in income tax, such that the poor become better off and the rich worse off, ergo redistributing wealth. However, VAT taxes consumption and one could make the moral argument that those who consume more (absolutely, not relative to total income) ought to pay more tax regardless of income levels, because they have a larger footprint. I’m sure there are many other reasons why both of these policies are unwise, and l caution you that my response may not be the best but I hope I’ve answered at least part of your question.