Cymek said:

If you run a Facebook group with 100’s or 1000’s or members what point does asking them to say hello serve.
They say its to see who is active or not, but what difference does that make.
If you post an article its not like you have to individually send it out.

Engagement is important so the algorithm shows it to all the members, and is a suggested group for everyone else. The more people who see it drives ad money for Zuck.