I think most of what you said is incorrect. You need to chat about this with high school teachers. From my personal experience and that of my friends who have teen kids right now -- Talking to kids about these issues is useless; they will say anything to keep the opium coming. They might be aware that spending a lot of time on social media and cell phones might result in slipping grades and homework not done, but they will spend hours on both, regardless of consequences. A lot of emotional anguish will come from social media, and kids on social media are generally a lot more nasty to each other than in person. There are so many tears because of what he/she said on discord... especially girls, being more emotional, cannot mitigate anything at all. These things suck them in like a drug, and parents' action is often the only way out. A blocked social media and kids' cell phones on my desk until homework and chores are done was the most important factor that helped to turn their grades around, and I know a lot of other parents who gravitated towards the same thing.