The World Would be Fraught with Less Drama and Pain were it Inhabited by Folks of Just One Sex

Witness the wild shenanigans that guys perform in hopes of impressing gals: crazy stunts, fights, murder, even running for high office.
The famous British soldier/author, T.E. Lawrence (better known to some of us as Lawrence of Arabia), was asked "Why do men go to war?" His still famous reply was "Because the women are watching."
This behavior is nothing new, nor are the women always innocent. Back in c. 30 AD, John the Baptist really teed-off King Herod Antipas' wife/niece, Herodias, when he said that it was unlawful for Herod to have her.
You see Herodias had previously been married to her other uncle, the king's brother, with whom she had a daughter, Salome. Herod divorced his wife and ushered Herodias into the castle. The fact that Herodias was an unabashed social climber may explain fully or in part why she was so royally enraged by John's pronouncement that she and the king shouldn't be shacking up. Unlike the king, her hostility towards John never diminished and she badgered Herod to the point where he imprisoned John.

On his birthday Herod threw a royal bash of the first magnitude. Knowing that her great-uncle and stepdad, the king, was a big tipper when he drank, Salome performed a humdinger of a lap dance for the king and his cronies for which the king offered Salome anything up to one half of his kingdom (HELLO! Herod, do you think maybe your judgement is a tad impaired?). Salome ran to Mom and asked, "What should I ask for?" Mom replied, "Well honey, do Mommy a favor and ask for the head of John the Baptist delivered on a plate."
"But Mom, that's gross! And anyway what do I get for providing the adult entertainment for the evening?"
"Don't worry honey, Mommy will take care of you."
So Salome returned to Herod and told him that she wanted John's head on a plate (for crying out loud!). Herod was bummed out big time by that request but he had committed himself in front of witnesses so he threw down another shot of shekar and said "Okey-dokey". John's head on a plate was promptly delivered to Salome who brought it to her mom who beamed saying, "Sweetheart, you're the best daughter a mom ever had!"

On the other hand, the trouble with only one sex would be as follows: if there was only one sex there would only be one generation and even if that generation lived for hundreds, or even thousands, of years there would be no magical, romantic times of mutual discovery shared by a man and a woman, both Homo sapiens, but each fueled by different octanes-- one by estrogen and the other by testosterone. You could never experience the miracle of one plus one is equal to or greater than three, resulting from two lovers that brought unique progeny into the world. Nor could you play the old "pull my finger" prank on a grandkid. In short it would be boring.
To quote lyrics from a song that Garth Brooks made into a hit:
"I could have missed the pain,
But I'd of had to miss the dance."