We need young people to pay for old people retirement (economically speaking, someone has to be working when someone else is just eating).
If the benefits of increased productivity went to the people instead of the 1%, you wouldn't need a growing population.
Why? I understand that's how the system works now but does it have to? Productivity has never been higher.
Why though? All those old people paid in all their lives so surely that is sitting in a vault somewhere waiting for them.
If they were only eating there would be no problem. But they want fancy vacations. They want houses. They need drugs. They need MRI machines. And they need these things for decades for minimal cost irrespective of ability to pay. And, when they do die, they expect to pass estates tax-free to thier children. Supporting the retired population is one thing, but the day may soon come when we revisit what it means to be retired.
We need young people to pay for the billionaire subsidies (economically speaking, someone has to accumulate all that profit and it's not going be us)
I really hope that automation and robotics will _finally_ allow us to invert the pyramid.