Choices for lots of Americans look like this:

Invest some money or have your aching tooth filled?

Invest some money or fix your car that you need to get to work?

Invest some money or buy diapers for your kid?

Invest some money or see the doctor?

Invest some money or replace your worn-out socks and underwear?

Etc.

Millions of hard-working, educated people can't quite cover their fixed expenses, no matter how frugally they live. It's ridiculous to pretend they could save and invest money they do not have.