> ...I don't really feel responsible for every human on the planet, or even a significant percentage.
That's fair and totally 1000% reasonable. However:
What if (whether through sudden injury or the accumulated injuries of aging) you become utterly unable to work, you've burned through your savings, all your family is dead, and you're an unlikable cunt [0] so those around you are supremely disinclined to provide assistance? Should you be cast out into the wilderness to starve?
What if you were born permanently unable to work and utterly unsympathetic? Should your fate be to die of exposure?
[0] I cannot stress hard enough that if you think I'm making comment about your character, please do remember that I absolutely am not. I don't know shit about you, so I cannot comment on your character. However, injury, illness, and prolonged bad periods can absolutely turn someone into an unlikable cunt... driving away a predicated-on-tolerability material-and-emotional support network just when one needs it most.