Yeah, as an only child it's a weird burden to be the guy who makes or breaks the whole bloodline. No pressure right ;)
But that pressure is on the parents too. There's this weird two-way feedback loop.
Single child household has made parenting culture neurotic. Because if you screw it up it ends your entire bloodline.
But the neurotic attitude makes child rearing feel like such a burden, people can hardly imagine doing it more than once...
I am told this attitude does not produce beneficial outcomes in the children either. Apparently people grow up healthier when their parents are relaxed.