Read what he wrote again. The scenario he created (everyone works, then everyone retires) has never and will never happen. Humanity is more likely to be wiped out by a meteor.
> Humans took care of THEIR elderly.
Point me toward the non-human elderly being supported by the social safety net. We're all related. You just have to look back far enough.
> Pretty sure most people don't want to see old people begging for food on the street but also prefer not to pay much to have it resolved (varies by country and culture)
I agree with you here. People don't want to help others, and don't want to suffer the consequences of not helping others. People are conflicted creatures who suffer from a long https://en.wikipedia.org/wiki/List_of_cognitive_biases