If companies are motivated and parents are motivated to prevent it and schools have the cover to also police it, then social media usage probably won't hit critical mass for kids and they won't feel FOMO to get it.

"it's illegal" is usually a decent enough hard stop to most kids for "why can't I have it"

Should just age-restrict smartphones altogether imo lol. Entire generations survived without mobile phones and it would remove entire issues around addictive mobile games, social media abuse, attention/focus issues