b800h parent
This is the same in British English. I found the main/master switch absurd. I went to school, and was taught by masters: an English master, History master and so on. In my cultural context, the switch was just cultural colonialism from America.
This is the same in other European languages. For example in Polish, the equivalent word, "mistrz", refers to all the things GP said, but doesn't even have a meaning that could be applied to slavery.
As for American English, wake me up when they rename Master's degree.
Well, the tide is going out now. That's unlikely to happen until the virus mutates and reappears in thirty years' time.