Back when smoking was more normal we basically did leave it up to Big Tobacco to determine how best to tackle underage smoking and they would literally say insane things like “Oh course we’re not targeting elementary school kids! We’re not monsters! Our advertising doesn’t hit them until they’re in 8th grade at least!”

Expecting platform monopolists and dopamine dealers to design for this is folly. They are wired to try to normalize an unhealthy level of dependence on them. Their business model is addiction.