I think This stuff depends on values in the home and what is taught by the parents. My two kids were also at schools where there were very strict rules against social media all the way until college, at least during school hours. For my kids, their phones are a tool. I’m not saying this is the same for all kids because I see how others are affected.
It is also very dependent on the friends the kids make which is out of the hands of parents unless there are red flags. If one's kids are friends with other kids who use social media then it is unlikely, regardless of what's taught in the home, the kids will not use it too. Plus, not all social media is bad. Just like anything else, it is how you use it.