No, you don't need "superhuman levels of willpower to avoid social media entrapment". Just block the damn sites. Delete your account before you do. No you don't need to keep up with Timmy from the 8th grade and his third marriage and worsening benzo addiction.

People smoked for the same reason people doomscroll - anxiety.

You can expose your kid to technology and also explain the role of moderation the same way you do with candy and sweets. You will need to model the behavior you want in your kid - that means putting your phone down. Buy a timed lockbox if that is what you need.