I live in the US, have a decent-paying job, but I don't have any kids, and I got a vasectomy so it seems unlikely that I will have any kids. If something happens by accident (e.g. the vas deferens heals), my wife and I would almost certainly keep it and we'd be parents, but I don't think that's terribly likely.
I actually do really like kids, I like my nieces and nephew, but the problem is that the value proposition for having kids is not terribly high. They're expensive, and time consuming, and honestly kind of a liability. It's especially hard for women, because pregnancy takes you out of the workforce for a long time, and women are still (however unfairly) typically the "primary caretaker" for the child. Since your 20's are generally the optimal time to grow your career, it's an extremely high opportunity cost to have a child.
I've never wanted to have my own kids. My wife and I have agreed to take care of our nieces and nephew if something happens to their parents, but I don't think I'd be a terribly good parent, and I would prefer to avoid screwing up another human.