so we learned
It sounds like you were like most people in the western world - uneducated on nutrition, cooking and basic life skills. This isn’t a jab at you this is just the world that we live in. Most people don’t have a good understanding of these things so the go with what is easy, fast and feels inexpensive. This drives obesity.
It’s great that you took the initiative to learn home economics and it sounds like it has helped you and your family. Many others have not gotten to the “so we learned” stage yet for whatever reason.
For the last 50,000 years or more we had to walk and move constantly to survive as a species so it makes sense that our bodies would have evolved to reward us for moving.