While you're right in that a higher VAT __can__ reduce the effective purchasing power, it doesn't have to. 1) Yang's VAT was at 10% which is under half the rate of most of the European countries. So I'd feel confident that we could follow similar procedures, which would halve the deficit spending (if the carbon tax was doubled to $40/ton, there'd be a surplus). 2) VATs don't have to be applied uniformly. I'm also not opposed to a wealth tax. But from my understanding, it is harder to avoid a VAT. This is probably an easier loophole to close (and Republicans like consumption taxes, so easier to pass). But you are right in that things would need to be reformed dramatically to actually capture a wealth tax.

I still do not buy the argument that a UBI will be shouldered by the middle class. I have yet to see evidence that it will be shouldered by anyone but the 1% (really the 0.01%).