I get that especially families in some regions having countless kids is probably not helping all of us. But not wanting kids to make the world a better place is having it backwards. We need to make the world a better place precisely for our kids.

Leaving a mark by keeping our evolutionary branch going (aka kids, their kids and so on) is pretty much the only task we got from life. Everything else we are, feel and have accomplished exists exclusively to achieve this goal and won't have mattered the day the last of whatever we consider "us" dies.