It's not exactly speculation. The birth rate in much of developed countries is well below the replacement rate. Population decline is already happening in some countries. Looking at current demographic charts shows that the number of elderly people is growing fast, while younger generations are shrinking. With fewer children being born, there will soon be much less workers to support a lot more retirees. Pension systems, mostly designed for growing populations, will be in real trouble as fewer people pay into them and more people are taking money out.

And, if Congress had not given themselves interest-free loans out of social security to bolster the economy then we wouldn't be having any worry about whether or not we can afford to pay social security.

The real danger is that the money for social security that would have been growing and earning interest as it was properly invested was not properly invested.

They have phrased it as they didn't expect people to live so long, but it's not that. It's because they don't know where they're going to get the money to repay social security, when the reason why there's any danger of social security running out is that the money was mismanaged.

That's what they've been saying about climate change as well. Think and you'll see why: people are trying to solve it, and then the beneficiaries suddenly think it's not a problem anymore. The year of exhaustion had recently moved from 2036 to 2035.