It is because we are slaves of our habits.
If your spending is low and your approach is always frugal you will never be spending more than you need but this mindset needs to be build in either by the parents mostly or sometimes the child during growing years learns this if they are intelligent enough.
Cutting down on habits that drain out your pocket is important to save money in later life once you recognize them. Use the public transport, get some steps in the walk to and fro and avoid using the car for short trips.
We can fix many things with very simple changes. The things you said are easy to implement and have effective results. In a way, acquiring habits such as using public transportation and walking to some places is beneficial to people. We need to review our habits and avoid doing the wrong ones.
The right moves regarding spending can make great contributions to a person's economy. Giving up unnecessary spending and habits that harm people will have a positive effect.