and yet most humans continue pursuing a lifestyle that is simple not sustainable at an 8 billion people scale, and don't want to give it up. Doesn't sound like they care much about the consequences of their actions on others.

Haven't made the calculations, but I'm quite sure we could keep the current technological pillars of well-being (food, health, heating) without much issue to the environment if we gave up all the other superfluous crap (private cars, gadgets, plastics toys, 3d videogames, etc). And we'd probably be much less depressed too.