Why do most questions here fall into 3 categories? Opinions?

What you say is true. I'm not sure why people ask them. Sometimes it could be an opinion question, ex: what should i wear with this, is this weird?. The search engine is probably because they're too lazy to do it on their on. And the go to the doctor, because they may think some doctors are on here, or someone with medical history. Thats probably more information then you wanted haha.