It never was.
No matter what the claimed reason for social security was back in the day it was really about getting Congress more money to spend right then and there so they could, in the words of The Gov from Blazing Saddles, secure their phones baloney jobs.
Typical of progressive money grabs (like those generous public employee retirement funds) those who benefited from instituting it would be long gone before the piper came around for his due.
Phoney baloney ... darn autocorrect!