As a teacher. Thats fine. With the side I'm using you have to "activate" the students to even being able to hear them. Generally I unmute only so they can answer to my questions or ask questions on their own. For students who don't like to pay attention this is bad, but at least now they can't disrupt the lesson and harras the interested students. For me it is much more relaxed. There is a problem with shy students not wanting to speak up, but generally the rest being muted / not being able to make grimaces helps with this as well. Now I wish for a mute option when we go back to school. Also my subjects are math and chemistry it's harder for stuff like languages and music.