You can do that via good parenting too. The myth of the self absorbed only child is just that, a myth.

My cousin is an only child and he turned out great and had a great childhood. I kinda envy the amount of family time and adventures they were able to go on. Part of it might be family culture, but seems like with one kid you can "do" a lot more, where as with 3 kids, doing things were often frustrating endeavors and just "maintaining" was more the norm.

This is true. But I was thinking more about just getting through life. Governments and pension systems come and go. But as long as you have living siblings, you’ve got pretty damn good insurance against all the stuff that goes wrong in life.