It is about the investing, with returns likely higher than social security. So people have a little bit more than SS only. Because SS was never intended to be THE SOLE resource in retirement.
I remember what you said about your situation (nothing left to invest), and I am sorry it turned that way for you. In many countries, to help families with children, there is monthly financial help. It was in USA also, as a part of COVID help, $350 per child monthly. It was terminated on partisan grounds, even if that was the simplest and cheapest way to improve demographics in USA, IMHO.