1) They grow their own food, work near their home, drive electric vehicles, have solar panels in their homes, recycle...
But the market produces what people value. If people demand self-destruction we're doomed no matter the system.
Environment greatly shapes behaviour, so it does matter, a lot.
2) Why there's no full employment?
Technological unemployment makes it physically impossible.
The reason we have so many people in the service sector doing useless stuff if because the mechanism of society requires people to work to survive, but it goes against the very nature of the advancement of society.
Why homeless aren't hired for food wages?
Of course, first of all, there's violence and wars. That's the case of many countries in Africa.
Then there's regulations, for example, minimum wages laws that prevent the less productive people from working.
And finally there's capitalism.
With capitalism you don't have only to produce as much as you're paid, workers are treated accounted like rented machines (capital) and (as I explained earlier) they have to be as productive as money or they won't be financed. The productivity of the monetary capital is the interest.
This way interest prevents full employment.
Maybe I'm mis-reading, but I don't see how that addresses the issue.
AFAICS, both issues are not designed to be solved in a profit-based system.
Since they are the fundamental principles for survival, I'd say it's about one of the biggest failures you can have as a societal system.