It complicates things quite significantly. In fact, if you were to remove this constraint then the problem becomes much more tractable. This factor alone limits you to urban locations because public transit alone is hard enough to find and absolutely nowhere in the US had decent public transit outside of an urban core except for a few cities that are already expensive to start with. There are not many of these places where you are not going to be competing with either university students, well-paid 20/30-somethings, or both.
To be honest I don't think any American city is going to provide this and until Americans get over their automobile fetish I don't think any place will even try to serve this requirement. It is quite normal in Europe, but only big, expensive cities work well for people without cars.
I'm wondering if you've thought of how much having that portable income would have helped you if you were actually able to drive.
If 90% of people with portable income were able to drive would they be able to move to cheaper places successfully? If that were to happen then the 10% who couldn't drive would suddenly find less competition (and therefore lower costs) for renting places in the areas that actually had good public transit options.
My medical bills are supposed to be thousands per month. I live on under $2000 per month most of the time. I am vastly more productive in dry areas with little ragweed and I need much less in the way of medical care.
This is part of why a lot of these one-sized-fits-all solutions for poor Americans are fundamentally bad ideas: They optimize for one metric only -- upfront cost -- and completely ignore large numbers of other issues.
The reality is that "cheap" solutions are often very expensive. Poverty is an expensive way to live.
If you look at the lifetime cost of a solution, the "cheap" answer is often the absolute most expensive in the long run.
Saying poor Americans with portable income should just leave the country doesn't strike me as a real solution, for a long list of reasons.
As the American population ages, this is increasingly becoming an issue. If you need to drive to maintain your independence, you lose your independence when you can no longer safely drive, possibly because you simply don't see well enough anymore, even if you are otherwise competent.
My sucktastic eyesight is part of why I no longer drive.
One of the issues in the US is that small towns and rural areas often lack high speed internet. If we could spread high speed internet to small towns and rural areas, that would help. It would make it easier to shop online for things not supplied by local stores, keep yourself entertained, do some socializing via internet and even have an earned income as a remote worker if that's what you want.
This was one of the things I checked for before moving to a small town to get back into housing. Since I do earn money via remote work, I need reasonably high speed internet to make my life work. I can't function on dial-up speeds.
Many people casually suggesting poor people should move to cheaper parts of the US don't seem to realize that those places may not have high speed internet. Good internet access can go a long ways towards making life without a car work. If you have neither a car nor good internet, moving someplace cheap in the US can be a serious hardship that cuts you off from having much of a life at all.
Finding something under $550 almost anywhere I'm the US that isn't senior housing or a trailer is challenging. They exist, but it's not as readily available as many people seem to imagine. There are places for less than that, but if you expect some kind of decent housing on a budget, it's a tough thing to find.
I live without a car and that complicated things. A lot of places don't have walkable neighborhoods or good transit. If you need a car to get around, that substantially increases your real cost of living.
I get really tired of repeating myself on this topic. I also worry that I will get viewed as someone harping on it or with a political agenda for simply trying to rebut the endless statements about how poor people can just move someplace cheap.
I'm poor. I have portable income. I'm a former military wife who doesn't mind moving. And I found it incredibly challenging to find someplace to move that I could afford and where I could readily access basic essentials like groceries and good internet service without a car.
If "just move someplace cheap" was all it took, I would have shut up about my problems years ago and just sat around humming to myself about how slick I am and how all the other poor Americans are just dummies who are doing it wrong. It's really not that simple. Even if you have portable income, finding an affordable, livable place in the US is challenging.