The purpose of a system is what it does.
All this talk of what it could be, or should be, or was originally envisioned as is nonsense. It’s the kind of shit leftists tell themselves trying to justify their good intentions when their desired policies inevitably fuck things up and they want more intervention to fix their last round of mistakes.
If people want retirement money - save it yourselves. You don’t pay into a goddamn ponzi scheme reliant on perpetual currency debasement + population growth.
There is no need for a “system” for this, humanity survived Millenia without one and only started doing this shit in the late 1800s when Statism took off. There is no such thing as “properly managed” when it comes to Statism.