Yes that model has been inverted.

The family used to tax the grown or mostly-grown children in the form of farm labor. The government in many prior centuries taxed like 2-5% total and the rest was intrafamilial support.

Now it is flipped on its head. Everyone else's families tax your child for their social security, socializing the benefits while still you retain most the costs privately.

Thus tragedy of the commons situation. Why make that investment when you can just tax everyone else's kids and rest assured of your own social security, if they don't pay it you can just have them tossed in a cage or their assets seized, no need to have children yourself.

What you write is the mathematical fact of societies with flattened and upside down population pyramids and wealth transfers from young to old, not sure why you are downvoted.