This is an incredibly new development and is based entirely on prosperity. For most of history of democracy and capitalism, individuals made altruistic choices

This is an incredibly new development and is based entirely on prosperity. For most of history of democracy and capitalism, individuals made altruistic choices for their own future generations - not for humanity, but for their own children. It's only during the post-war boom (and only in the countries that were undamaged by the war) did automatic prosperity become the ubiquitous expectation. And even in that context, immigrant parents made similar sacrifices.