All Endermen that existed centuries ago had intelligence and could build things such as End Cities. Even though these beings had such great power to build and teleport, it eventually sealed their fate when they summoned the Ender Dragon, and trapped themselves in the End and in the Overworld.
Over the years, the Endermen lost their intelligence and now they don't have any knowledge of building, only knowing how to randomly pick up and place a few blocks. Time and Mother Nature have tamed the Endermen, leaving them as helpless animals.

Although the tragic evolution of the Endermen sealed their fate, one stood out from the rest. He was smart and knew how to build. Better yet, he still knew how to craft items! This ancient Enderman survived the destruction of his race and remained untamed by by Mother Nature. No one knows how he survived for this long but we do know that he is skilled in the art of magic and brewing. Many theories say that his power and potions kept him alive all these years, but what's the real truth? What the secret behind the Untamed Enderman?
If you ever see him, don't look into his eyes. He is much more powerful than normal Endermen and will kill you. Good luck!