That isn't really true.
Social Security is a Ponzi Scheme. A Ponzi Scheme needs a constant and increasing supply of new victims. But, adding victims only prolongs the life of the scheme a bit, and adds in an absolute way to the inevitable agony and misery at the end.
On the other hand new victims do help the early co-abbettors, the "early-ins" that reap rewards from the later-comers, and stand as supposed evidence that the system works. These are the people that now belong to AARP and don't want their gravy train interfered with, no matter if that train will take the whole country down when it finally crashes.
Yes, it is a Ponzi scheme. And the oldsters, who vote, won’t hesitate to raise taxes on their grandchildren to keep the gravy train running.
Nothing will be done until the system runs out of money.