It may have been promoted as a Government resource (rather that charities and churches), to support the disabled, elderly, widows and orphans - but when the Feds mandated deductions from the working poor they called it a ‘future retirement benefit’.
Indeed, but it was not originally intended to be something to benefit the large middle class that appeared after World War II. Like the withholding tax, it served as a handy way of capturing a larger share the wealth that fell into the hands of a growing middle class than they might have. Excerpt for withholding, companies might have simply paid workers a higher salary rather than buy health insurance for them, and started us down the road that ends with Obamacare.