"Sir" is derived from the word "Sire", or "seigneur" in some other countries, and it was a form of address used when talking to a feudal lord, possibly a knight or a baronet. It was used by the serfs. It doesn't really have a use in the modern world other than as an obsequious form of address used by a shop assistant or waiter.
I don't know much about Western knight culture, but in some ancient cultures in the East, the word “Sir” has a similar usage to the West in ancient times. sometimes, it is used to refer to feudal lords who have no title.
But now, besides I can hear the waiter call me like this, I can rarely hear who called me like this.
At least in our country, it has some derogatory ingredients in it, Perhaps the word has no derogatory use in Southeast Asia and is more widely used.
If anyone knows more about the usage of this word in Southeast Asia, you can make an explanation about how use of this word in Southeast Asia.I am very interested in this.