Medicals know how to use one and which ones to use. For them it is a real protection for themselves and their patients.
Some of them here act like even they think it’s overkill but they do it and require us to do it too. I think it’s a good thing for me during flu season so I do it without being told. I retired from a battery manufacturing plant and we worked around very dangerous chemicals. We wore N95’s but had to go through training to wear them. I have several that my husband wears to the doctor. He retired from the same place I did so he knows how to wear them. I wear the regular 4-ply medical masks in public for flu but I don’t trust them for COVID so I still stay away from people and keep my hands clean especially since most people here don’t wear them. I was doing it before it was COVID cool.