This is likely the stupidest thing I'll read this week, thank you for that. In what way, exactly, are children not expensive? From some research and napkin math

This is likely the stupidest thing I'll read this week, thank you for that. In what way, exactly, are children not expensive? From some research and napkin math, it looks like $300k, not including opportunity cost (so in reality more like $500k), if everything goes right. Hope there's no medical issues, hope there's no car crashes. How many years of salary is that?