Nailed it with "or carry cargo". Every week I drive to the supermarket and pick up 20-30 kg of stuff[*]. It pretty well maxes out my Golf trunk. I couldn't possibly lug that stuff even 30 meters, let alone 10 km to take it home. No; sorry; not even with a hopelessly cumbersome cart. I'm 69 and pretty-well busted-down. I'm doing pretty well just to walk through the store and COLLECT the stuff. And no, nobody will deliver it, even if I had two pennies to rub together to pay them with.
You can say I'm not worth society "allowing" me to live at this point; I'll just say I'm self-sufficient as long as I can make that short drive, and the drive to the post office. I use no more than 1/2 gallon of diesel fuel per week.
[*] 3-4 gallons of spring water (I drink a lot of water), other bottled drinks totaling at least a gallon, a pack of 12 Ensures, cans of soup, etc., etc.