Every time, it's the exact same argument, "if you give the poors more, everything will cost more, and they'll be right back where they started." And, well, we didn't always look like this. Obviously it's possible for there to be a different equilibrium in society, one with less disparity. So something has changed.

Seems like there should be ways to change it back, even to the disparity we had (overall, I know life was horrible for PoC) in post-WWII America. That'd be a step up from this.

A dozen people erect tents and lean-to shelters out of ad-hoc materials on a city street to stay out of the weather while they sleep. They use the gutter (or not) as an open air latrine. If a BI system is providing them with some money which they can apply toward a system of shelters or temporary living space, I "receive" an environment where I'm more productive because I'm not worrying about the people living on my doorstep. That is worth a lot to me, and I can unilaterally start giving money to anyone sleeps in front of my house so that they can get a room at a hotel or shelter bed but it doesn't change the systemic reasons that person is sleeping on the street. Now if I give them a BI stipend and combined with wages they get from working they can find a shelter, then not only are they better off but I am better off as well and the economy as a whole is more productive.

That is achieved by capturing some of the excess wealth being generated by the economy and directing it toward the quality of life improvement for everyone (the homeless are housed and I don't have to dodge their encampments on the street and city services are more able to cope with people living in expected places and provide garbage and sewage services.

Your comment hints that the government (federal or state) will be the employer and the work will involve public works of some kind. So far, neither have been interested in actually doing these kinds of projects despite the need. Maintaining such project is also a concern: in an area where the income of the population is tied directly to public works projects, what happens when these projects come to an end and the population returns to unemployment?

The current regime explicitly excludes those who do not have income. Whenever we talk about helping people in poverty in the US, we inevitably circle back to tax breaks. If these people have little or no income to begin with, in what way will tax breaks help? If so many decisions are going to be made based on "the market deciding", how will they participate without enough income? If we look at broadband access in these areas, we'll see vendors complaining that there's no point in rolling out service if no one can afford it.

Basic income will allow these people to participate in the market and, hopefully, in their local economy. They will decided what projects deserve funding based on the way they spend their money.