Fails short, because for all species but humans, reproduction/offspring is kind of the main goal in life. Humans have a lot of other interests, and having chil

Fails short, because for all species but humans, reproduction/offspring is kind of the main goal in life. Humans have a lot of other interests, and having children comes with huge tradeoffs in "lifestyle". Also, they can actively avoid pregnancy. Which other species does that? Edit: What would phase 3 eventually be, if you overcame all obstacles, but children still take away from other activities? I think this reason alone is enough that most people will be happy with roughly 2 children. Enough to fulfill the desire for children, leaving room for all other things in life.