If you actually lived in a society where there are cheap apartments in walking or biking distance from reasonable urban infrastructure and all the job that are there. So that you don't have to pay for your commute, or have some very local public transport.
That is what actually safes real money. That is how people in really poor places, like the Eastern block could reasonably approach a decent standard of living with far lower GDP. They lived in apartments, and had most things they needed close to them.
That is how you systematically can even approach to solving these issues.
If your analysis is restricted to, poor people can't utilize economics of scale on an individual bases, then you have a flawed view of poverty.
Consistently housing cost and transportation cost approach almost 50% of total living cost even for the middle class. And more then that for the poor, add food and you are going 90%+.
So if you can systematically so something to reduce housing cost and transportation cost, then you are actually changing lives on a real scale. Far more then buying food in slightly larger quantities, far more then buying slightly higher quality shoes.