I chose generic index funds; there was no stock insight assumed.

Oh, I know. But that's because you have financial literacy that people who self-selected to be on the Fool. A very large proportion of people, if you let them just keep that money they're not going to prudently and diligently save it for retirement. We know that, because befpre we had social security they mostly didn't save for retirement. You would have, but far too many people wouldn't.

You can't just let people choose not to save for retirement. And the federal government has no mechanism to force people to save for retirement. All they can do is tax in order to fund a social insurance program.

Are you aware of the historical return rate for the S&P 500? It's between 10 and 10.5% over a period of 98 years.

Yes, I know that. The reason we know that is because it's already happened. We now know that's what took place, but these types of government programs have to plan for the contrary possibility. That we're in a different timeline, one where stock markets don't return that high, but the government still has to pay for all those folks' retirement years. They have to plan for the possibility of a 1989-2019 Japanese stock return, not the stock returns that we ended up having.

The government has to treat SS as requiring a true risk-free asset. And the actual risk-free investment is almost always going to be the asset with one of the lowest returns in the economy (because that's pretty much how finance works).