It's basic economics in the sense that it's an oversimplified toy model. In the real world, every country I'm aware of gets a substantial amount of its tax revenue from consumption taxes, and indeed the US's lack of VAT means it's currently much more dependent on progressive income taxes than peer countries. (https://www.oecd.org/content/dam/oecd/en/topics/policy-sub-i...)
I responded to a comment that called progressive taxation a crazy “far left” idea - I’m not sure the second and third order details of taxation policy are really relevant here…
But ok - yes, sure, in real life it’s a mix and the mix is worth debating. Note also that consumption taxes often have exemptions/reductions to offset the most severe regressive effects.
