It's not what I would call pleasant, their are few jobs, and transportation is an issue. However, basic food and shelter can be really cheap.
Not sure what I'd do near retirement age in that situation. I'd be torn between staying near work I might not get for age discrimination reasons, and building a retirement cabin to see out my days looking at trees and surfing the net. If I had health issues I might want reasonable distance to doc and hospital.
PS: Medicine is also a huge issue, but such is life.
The real issue is many structures are designed to be actively cooled so they get much hotter than ambient temperatures which is an issue. The urban heat island effect also tends to make thing far worse for homeless populations.
People will also do things like fill a cheap kiddie pool with water under a tarp which will take the edge off. In extreme days you can even add some ice cubes to that, but just as heating a kotatsu is much cheaper than heating a room this is fairly cheap. https://en.wikipedia.org/wiki/Kotatsu
PS: I recommend using a comforter to make a low cost Kotatsu out of a computer desk in you use your PC near the window in the winter. You stay comfortable at a much lower room temperature.
That specific case may have all kinds of issues, like any purchase buyer beware. You generally want someplace close to people that let's you live there. Further, transaction costs are not free. However, the point is land is cheap, making renting it cheap, not that someone would necessarily want to buy any specific part of it.