You don't have to get interest in order to live on savings.
If, for example, you make 5 times what you spend, you could work for 10-15 years, and live off of savings the rest of your life, even if you got no interest (or equivalent).
If everyone were to think in MMM / YMOYL type terms and buy less crap, there would be less work that needed to get done, and early retirement (or 5-10 hour work weeks) would become the standard normal