Modern application cases of traditional etiquette

To give a simple example, before you enter a teacher's office or someone else's company, you should knock at the door, instead of pushing the door directly like entering a public place. This is a polite behavior and a kind of respect for others. Etiquette is advocated because we can make others feel respected through politeness. For example, it is polite to say goodbye to others on the road. For example, being careful on the road makes people feel warm and caring. This is also a function of etiquette.

This is a personal opinion. I don't know if I understand correctly.