Most reptiles and amphibians could care less about their babies. For mammals, quokkas get pretty close.

Human nature is to act as you do and the systems we've built are most successfully navigated selfishly, unceremoniously and without sentiment. It's gross and hopelessly shortsighted, but it's also not the individual's responsibility. Tragedy of the commons problems are handled at the societal level and declining civilizations just don't do that.