Interesting analysis on writer styles. I think most writers would classify themselves as #1 on your paradigm.
Having spent a lot of time on other forums, I would say the quality of writing on Medium is significantly higher. I seldom see any bad articles.
Most Medium writers are at least competent; some are good; some are great. Which writers who win the Medium lottery and show up an many feeds is a mystery to me.
If I were to classify Medium writers, one category would be writers who have a reasonable Medium paycheck as one of their goals. I think the Medium psychologists try to keep this group in the game as long as they can. Unfortunately, many of them just don't have the edge to be the next Hemmingway.
If Medium does somehow prioritize only the truly great articles, many of the above writers would disappear. These great articles would be less read than they are today. Very few people here would put their $50 down just to read.
While many Medium writers do read other Medium articles, deep down inside their subconscious, something is saying: "I much prefer to be read than to read". I would put myself in that category.
Maybe Medium has found a reasonable balance at ensuring a somewhat engaged audience.