I think this part of the discussion is really interesting. After all, this is about discussing an actual solution to the problem of "extreme luck" (good or bad)

I think this part of the discussion is really interesting. After all, this is about discussing an actual solution to the problem of "extreme luck" (good or bad). I don't see your point, however. The authors explicitly say it should be a progressive tax and that income tax should be removed. That does not include removing tax on capital gains. So I understand the idea as taxing consumption after it reaches some minimal threshold, and otherwise only tax income from wealth. I don't see how that would affect the lower ranges of income other than that they suddenly would be relived of all tax burdens, and in particular, of their by far highest tax rate: the VAT. I also don't see how that "fucks the middle class" - for them, these changes should be mostly transparent. That is, for them, VAT and income tax will just be called differently, but the overall rate still should be about the same. The real problem arises with the rich, naturally, because their VAT will suddenly skyrocket. In other words, as the rich and powerful rule the world, this is yet another proposal that can't happen without some pain...