The Romans didn't have advanced computing power, and saturation surveillance with facial recognition, to track people from the moment they leave their home every day. They didn't have microwave emitters that disperse crowds by -in essence- starting to cook them (ADS; non-lethal because the crowds will move FAST to get away YouTube: Non-Lethal Weapon: Active Denial System (ADS) (USFORCESTV)). The Romans had spears and swords, and -at most- nosy neighbors.

As for China...they only spent a short amount of time without emperors in some form. The ROC didn't last long, and is now occupying Formosa. Mainland China has an "emperor" named Xi today, the latest in a string of anointed leaders since Mao.

The Vatican was, and is, authoritarian. Not sure why you brought that one up. The Pope shall not be questioned, especially if he sits in his special chair and wears his funny hat (then it's "papal infallibility"). It has never been democratic. You know as well as I do that religion is the pinnacle of intolerance. Where it can ban free thought, other religions, and/or non-belief, it does. For a long time, bishops and cardinals had almost as much power and governors and kings.

England is an interesting example. They've had kings for over 1000 years, except briefly when they beheaded Charles I. They actually rid themselves of the monarchy, and then decided they wanted to restore it with Charles II**. Somewhere along the way they established a parliament, but they still have a king. Though, to be fair, the Torries were tossed last election, so they have slowed their slide towards xenophobia and totalitarianism.

**At the Tower of London I chatted with a person who stands around and makes sure nobody touches anything. She knew the history, but was unable to say why they restored the monarchy after having abolished it. Other than people thinking it was "better" under the monarchy than in their fledgling democracy. So they voted for a dictator/authoritarian/king to return.