Most people don't find meaning in the raising of children. It changes your life a lot, but if you feel like your life is aimless and you're just on autopilot, you'll probably feel the same after having kids. It's rare for a person to define their purpose in terms of their kids and be happy about that. Most people still want to have a self-actualized purpose.

They (children) also change your priorities (...and time, plans, budget...whole life)