I would learn more doing it on my own
Fact or Fiction? Fiction
While this may seem true because you'd have to do all the work, group work usually allows you to include more research than you could alone, exposes you to perspectives you wouldn't hear otherwise, and teaches you about your own writing strengths and weaknesses in ways writing alone and just getting a response never can. Thus, in group work, you learn more about writing itself, and, if done right, the topic as well.