It is also psychological trickery. When someone is correcting you, observers of that interaction are unconsciously signaled that the person correcting you is above you int he social order.

This is the same kind of trick they use with Kamala Harris' name during the campaign. When they are correcting you on how to pronounce it, it sends and unconscious signal that you are inferior to them in some way.

It also establishes power. If someone is able to control what you can and can't say, then they are in charge.