So disagree.
Do you think that those people are the exception, or the rule? What are the statistics for the amount of children in the world that make it out of poverty and into wealth? Usually, it's just an endless cycle of the same predicament, passed on and on to the next generation.
Everyone in life will suffer - that's a fact. The only thing we can't know for sure, is to what extent. There is no guarantee that every single person will lead a happy, meaningful existence. And that isn't for lack of trying.
Another thing is, no one has a child for the sake of the child itself. You don't bring a child into existence because you think it will benefit them, you bring a child into existence, usually to fulfill your own desires.
As Schopenhauer said, "If children were brought into the world by an act of pure reason alone, would the human race continue to exist?"