The Heir To The Kingdom Of 1.4 Billion Citizens

Xia Mingyu accidentally traveled from Blue Star to a different world similar to the Fantasy medieval world, but everyone has a row of identity tags above their heads.
Civilian tagger: Struggle all your life for a few pieces of black bread and a small house, tired all day long but terrified.
Aristocrats: Born with wealth, good looks and the power to break laws, they just need to enjoy life to the fullest.
King Tagger: I don’t eat beef.
Xia Mingyu, who is used to being a cow and a horse, thought that he would continue to be a cow and horse after time travel, but he found that there were already people kneeling beside him. It turned out that the label above his head was actually - heir to the kingdom of 1.4 billion people!
Xia Mingyu: "???"
No, where did I get such a big kingdom? Wait, in a sense, everyone is a successor before time travel...
A few years later, at the founding ceremony, facing countless eagerly awaiting citizens below, the first and last king Xia Mingyu said:
“I have a dream. There will no longer be serfs, prostitutes, slaves and other oppressed people in this land.”
“I have a dream. On the site of the former slave capital, the children of the former slaves can live with them. In the past, the children of nobles sat on the floor and were as close as brothers."
"I have a dream. In my country, no one will rely on the label on their head to identify a person's nobility, but on the quality of character and morality."
....
"My fellow citizens, although the road ahead is difficult and there are many temptations, please lend me your strength and realize these dreams with me!"
(Note: The protagonist will guillotine those who make prostitutes).