budget. Over time food has gotten cheaper relative to wages. That is why food storage, sewing, repairing your own vehicles was so popular back in the day because these items cost so much relative to wages. Buying powdered milk and putting water in the ketchup bottle made a lot more sense back then.

No one really produces their own food, repairs their own car, or makes their own clothes. These things aren't cost effective any longer, hence the church hasn't pushed these issues as much as in the past.

I don't think the fact you drank powdered milk was that your family was cheap, it just made economic sense back then.