What are the the benefits of joining the Engagement groups?

Does it generate more followers? I'm only using MassPlanner and only generate about 50-100 followers on a daily basis, which is very low if you ask me.

Well there's a big hint in the name. Engagement Group. They primarily help with engagement, you get more likes and comments on your photos so it looks like your account is more active.

Getting more likes can help you get more followers by ranking you for your hashtags or by exposing you to people via their explore page.