The idea of passing on to the next generation a world as good as, if not better than, the one we inherited is ensconced as a pledge in the Athenian Oath of Citizenship. It is a moral principle-- a tenet of fairness between generations. (See my research report "Deciding for the Future".)
I'm not sure my generation has fulfilled its duty; we are leaving some nasty messes and mighty dysfunctional institutions. Sorry about that, kids.
This article, "How My Generation Broke America"
tells a credible narrative, to me; it squares with what I remember and think about the events of the '60s and the decades since.
Our current state of cultural evolution breeds shorted-sighted self-interest, bloated addictive consumption, alienation from nature, and distracted self-indulgent lives. But parents everywhere and in all eras, I imagine, want their offspring to thrive-- almost a biological imperative, it seems.
Parental love and the family bond, not moral duty, animate the effort and sacrifice required to satisfy the principle of intergenerational fairness... for their own children, if not for the larger community.
In traditional societies, the elders pass on their wisdom to the next generation -- and its survival often depends on it. But under today's conditions, given the speed of socio-technical change, the fracturing of civil society, and the corruption of political institutions with the advent of the Trump era, the past is no reliable guide to the future. The world of the grandkids ls radically different from the way I grew up; any advice from my generation to yours would seem irrelevant.