There are two big things that can go wrong in group projects.
A. Your collaborators fail to do what you asked them to do/what they said they would do.
B. Your collaborators do so much you have nothing to do.
I've been the victim of A at least once in my life.
Yeah, I really don't like them. What's wrong with it is that I'm known as the "smart kid" so I'm constantly on research duty, but then people ignore it and it looks awful... but not all are bad! Just 8/10.
They make you do the research, and then they ignore the research. Do they take the time to do their own research if they don't trust yours? If not, they're truly lazy.