> have kids because they otherwise lack meaning

That's how life on earth worked for 3 billion years. I think that assuming humans are somehow above that is unwise. We're not.

Not to dismiss child labor laws. But kids until some 100 years ago were useful, free labor to help around the house or even with your business. The financial incentive of having a kid now is an astronomical investment.

I think, until very recently, people had kids because the sex is good.