In a way you made me laugh. Of course, if it's hard you prefer teamwork on the other hand those who don't find it hard are limited and have to share their notes with the teammate who finds it hard or worse a lazy arse.
What happens with those who work hard, the better students? They will be unmotivated and have no chance to grow.
Why not? Because if you want to learn something you have to be with someone who is really good. (works for you but not the one who is good).
Teamwork is with us the biggest frustration of good students, being forced to do the teacher's job by explaining and being limited.

If it comes to your point 3: it also makes people hate one another and it ruins friendships. A downside no one writes about how come?

Misleading title:

You don't host a contest so you are not allowed to use this in your title!

good luck and a happy day to you.