I used to turn them off, as i had a boss who loved to micromanage and would expect answers at any time of the day and week. However, I've actively started changing my dynamic with him, setting my boundaries, and I'm comfortable now him to see if I saw his message yet i did not answer yet.

As for social interactions, in Korea, it is not acceptable to see a message and not answer right away. But it is accepted to keep it as unread even when every knows you've already read it in stealth mode.