> I don't think many people ever doubted that giving everyone an extra $12k per year or whatever made out of thin air would help some people, but in real life, the money has to come from somewhere.
No, in real life money (especially in a country whose debt is denominated in currency it controls) is, almost literally, just made out of thin air. There are consequences of having more money around, and sometimes it is useful to destroy some money in a different distribution to offset some of the effects of creating money that was created and distributed a particular way, but that's a different issue. (This is the relatively uncontroversial part of Modern Monetary Theory; the controversial part is the follow-up “...and, therefore, we she engage in deficit spending a lot more freely than we do now.”
The myth of the fisc (a metaphor held over from commodity money times when it was a decent repres5 of reality) is that money has to come from somewhere.
> Plenty of people don't want to pay the increase in taxes that would be necessary to help the homeless publicly like that.
The idea that taxes are necessary to pay for spending is the myth of the fisc. It's true only to the extent that the government decides it should be true. (Which, as much as people in government talk about it when opposing spending they don't like or promoting tax increases they do like, isn't all that much, hence the absence of anything approximating long-term fiscal balance.)
> Whereas if you take that same increase in funding proposed and instead, say, expand housing programs, fund food banks, or provide mental health treatment, you know all that money is going to help people.
No, you don't; waste, fraud, and abuse in selectively targeted government programs is a very, very real thing, and a lot of the money that doesn't go into waste, fraud, and abuse goes into control measures to prevent waste, fraud, and abuse, instead of to the actual program purpose.
Source: more than 20 years in public sector work, the part of it that wasn't in IT specifically in fiscal management aimed at accounting for proper use of funds.