> But it is not self-sustainable and not good enough for medium-and-above income earners.

It seems good enough for median earners. After taxes and health insurance, it's basically even.

Perhaps not self-sustainable you mean that unless something changes, it's not going to be able to keep paying out at current rates.

Well, I got news for you - that's what is happening for almost all government-run pension programs across the world on this model. Pay as you go does't work when you keep the same payment, and have 10x a higher ratio of recipients to payees.

This isn't unique to Social Security or the US. It's just a mathematical fact of the system.

You cannot have 99% of people contribute `x` and 1% of people receive `y`, and then switch that to 70% contribute and 30% receive, without either increasing `x` or reducing `y`.

You could have planned ahead for this long ago, and seen that the ratio was going to change and increased `x` over time accordingly or planned to reduce `y` over time accordingly. But we didn't, and mostly no one else has either.

GP was confused probably. In EU when we hear a "pension plan" we usually think "social security", since we* pay a significant part of our earnings for this, so this is something we definitely count on and, at least in theory, it should be enough for good retirement (in practice it really varies). Many countries also have mandatory private plans that companies have to pay for, but I think people* think of them as "something extra on top" instead of the main retirement source.

*Asterisk because EU is big and diverse, and I don't know every country rules.