> In France it is reported that retirees now have higher (average?) incomes than workers

It may not be exactly true, but it's close to be true, and then like you said the workers have way more expenses (rent, children).

I will point out that in the 90s we in France already knew that the retirement system was unsustainable. It is quite obvious if you look for 2 seconds at the population pyramid :-)

Generations of politicians tried and failed to do something about it, thanks to the left (and sometimes extreme right wing) saying that there was enough money and we just need to tax the rich more.