In many (western inspired) parts of the world, the retirement scheme depends on productivity being increased for every generation. This because every generation that retires is larger than the previous generation that retired. The population growth drives the need for an increase in productivity.
You can increase the productivity by either increase the size of the working population, or make the working population more productive per individual. Up until recently we actually did both. That's why our elderly now can enjoy VERY comfortable retirements compared to two generations ago.
For us, those who are now working, it doesn't look great. We're not having children and it's getting hard to squeeze more productivity out of us.
Here according to the latest projections, I'm not supposed to retire until I'm 69. And this is with today's data. I fully expect it to increase further. Those that were born in 2015 or later are expected to work until they are 71, according to today's data.
The problem is that I don't think that on average we can work until we hit 70. My father's generation was quite broken right about around 65 when they retired.