Firstly that is easy to say when you are in the first half of adult life and/or healthy. You cannot know how you will feel about your life as a whole until you reach its end.
Secondly, the point of ruminating on this subject is to consider whether it is right to bring a child into the world. Most people conceive a child for ego-driven reasons. They fear mortality and they want a legacy, but they aren't solving any existential problems by having a child: they are just passing them on to the next generation.
Everyone needs to decide on their own answer as to whether it is right to conceive. I wouldn't criticise anyone for deciding to have children, but I certainly criticise people (if they have a choice, which, globally, many women don't) who conceive without giving any thought to the life the child may experience when older.
It's very revealing that parents are so uncomfortable with thinking about this. Every bit of suffering your children experience throughout their lives is due to your decision to conceive them. You might not like that thought, but it is true. Of course, every bit of pleasure they experience is also due to your decision and, for many people, the pleasure outweighs the suffering, but for no means all.
And I'll talk about what I like on this thread, thanks. Over-population and the narcissistic desire to reproduce are intimately linked.