What are some professions where most people in the field are actually quite terrible at what they're doing?

I had this discussion with a friend the other day, where we mostly thought of and talked about jobs where even the average person in that field is usually highly competent (like air traffic controllers).

Though I wondered if the extreme opposite exists, where the average person is quite often rather terrible at their jobs. I thought maybe there are people here that could share some of their personal experiences.