Engagement and retention are both important. If the solution to retention is to walk away then the solution to engagement is to not be engaged that doesn't track to me. Maybe the idea is to avoid phones, the internet and TV entirely which is not an idea that is grounded in reality.
This one is less interesting to me for some reason, I think it's an easier assumption to make or maybe it's that the argument about harmful algorithms gained traction over a decade ago.
This is an earlier paper but is a solid primer that touches on it
The researchers positively showed that news and updates on Face-‐ book influence the tenor of the viewing Facebook-‐user’s subsequent posts
Here's an entire book about it or an article.
Social media addiction has emerged as a problem of global concern, with researchers all over the world conducting studies to evaluate how pervasive the problem is.