Maybe didn't mean you, but the GP's "I have a hard time to see any relevance in a life without children anymore. This might be complete bs but certainly floats my boat." That sounds like it could make a kid think "So they didn't have me for my sake, just so they could find 'relevance' in their life".
I don't think there is ever someone who decided to make kids only for their own kid's sake because you don't know your child before they are brought to the world. Or least this is very hard to grasp.
Of course, adopting is a different wonderful way to have children where you can meet the child. But also in this situation: are you choosing one for their own sake or for you own sake?
PS: I have a kid and think a lot about the responsibility of parents to their children due to the fact that the parents decided to bring the children into the world.