Generally those don't have population wide, negative impacts (except maybe drinking). I would compare it more to smoking which is considered a public health issue and we regulated smoking out of the market through a combination of safety regulations, limitations on marketing etc. Age bans were part of that but the ID checking requirements there were substantially less risky due to little no risks of retention.
You usually apply bans like this to something that is unhealthy for _everyone_ e.g. smoking. So why isn't the focus on regulating social media to be better? It seems like it's not great for the whole population in its current form.