But the Ponzi scheme aspect of SS is (mostly) orthogonal to its "forced savings" aspect. If the revenues from its taxes had been invested like a sovereign wealth fund, even very conservatively, it would be in much better shape.

Instead, it was "invested" in government bonds, which is equivalent to saying, "oh, I'll just raise the money later". But that's courting disaster: if you have these unfunded obligations that come due, you have to gore an increasingly difficult amount of taxes out of your base, which can become rapidly impossible if and when people start fleeing from the burden.

We could have kept the forced savings but given people back more than a real dollar per dollar forced to contribute.