It’s more complicated than that. If there are a disproportionately little amount of young people who can work and run society, with a disproportionately large amount of old people who are retired and want a pension; society as a whole would begin to crumble. We need a healthy balance of young to old not necessarily so the capitalistic week can keep turning, but because we need more young to work so that the world can function and the retired can enjoy a pension and good quality of life.