Okay, so I will admit that I hadn't looked at Yang's plan prior to now because he's not a serious candidate, and he has no chance.
However, since we are discussing the matter now, I decided to delve into it.
First off, I see that indeed he's not planning to directly tax the rich in order to get the $2.5 trillion. Actually, it's $2.8 trillion, because the figure of the number of US adults I got was incorrect.
Anyway, he's planning upon a 10% VAT, which would be a disaster. Some states like California have regions with as much as an existing 10% sales tax, so this would be a huge new sales tax burden. It would also be a regressive tax and hurt the poor most. Laughably, Yang tries to address this by claiming that the prices of manufacturing goods would come down under this plan (???), so it would mostly offset the 10% increase in price. L O fucking L.
Also, the 10% VAT would fall way short of raising the required money, even with Yang's other proposals such as raising capital gains tax. It would only get about halfway there,
according to this study.
Again, this would also disincentivize minimum wage work. SPIT This tried to claim that it's not equivalent to the 99-week unemployment abused by OSA and others, as unemployment benefits don't allow you to work (at least not on the record), whereas a UBI would allow you to work without penalty. However, I think he's also not understanding how awful and tedious minimum wage jobs tend to be. People are creatures of habit. If a couple is subsisting on $24k per year -- or something close to it -- and they can get the same $24k per year while not working, they will maintain the same lifestyle and not have to work. This won't be true for everyone, but it will be true for a lot. You wrongly assume that they will go work a minimum wage job to make double the money. These jobs suck so much that the people holding them are really doing so out of necessity. Take away the absolute necessity, and a lot of people will simply choose to do nothing, or to take gig/part-time work in order to supplement what they need to get by.
SPIT This also says that the $1000/month will also replace the welfare system, and will save a lot of money there. However, the entire amount of welfare in the US is about $1 trilion, so Yang is essentially increasing this by a factor of 3. Even if you take all of Yang's awful proposals on how to raise the money, and even if you factor in the $1 trillion in welfare savings, we still fall short.
There's also the general concept that people are being taxed so everyone can get $12k/year for just existing, and that we will all be paying for lazy, able-bodied people to be able to get by if they simply choose not to work. I find that to be an obnoxiously unfair burden put upon those who put out the effort to work. The welfare system has long been criticized for the same reason, but at least there were some reasonable justifications (such as what to do with the single mother who can't make enough money to pay or childcare while she's at work). Here all of those justifications are out the window. If someone simply chooses not to work, we are going to support them anyway. Terrible.