They are absolutely not pensions, and you are not paying into it now to fund payment later. It's a tax. You pay it now to cover those taking it now, and the social contract says future generations will do the same.

This is a very important distinction, so I'll repeat it. Social security in the United States is not a pension, it's just a government program. We're told it will continue, but that's only because the current government says it will. A future government could just decide to stop payments, and there would be no recourse because it's not a pension. If you live in the United States, please plan accordingly.