The problem is that for many folks the amount they are making isn’t enough for them to live a very reasonable life AND they have nothing to invest in the first place. Suppose a household in a given area needs $100,000 to afford a VERY modest house in that area, health insurance, savings, healthy food etc. Now suppose the house has one disabled breadwinner and one fellow working for $40,000.
Because of this they live in shit town in a tiny apartment a building full of drug addicts in a not so great part of the state wherein the average life expectancy is about 10 years less than one of the good parts of the country.
The first 40k of “excess” would be spent on having a decent life, working a sane number of hours, moving into an actual home. For fully half the country the idea of having excess is laughable. It’s a crass joke.