Engagement in general feels low to me, not many posts have lots of comments, and certainly not deep threads of discussions, and these deep threads are some of the most interesting to read. This has given me an idea for an interesting weekly post 😀
There is definately a focus by many of the community on dishing out content rather than engagement on other peoples posts. I must dig out some stats on this but comments really encourage you to keep going with whatever it is your engaged in, be it community organiser, competition organiser, Content creator ...
There may be features to some of the front ends that could help here. A random idea is a visual que at the end of a message indicating the authors call to Action. This could even be tied to a share in the post rewards for all the people who contribute (or just a big upvote).