To add to your response to #2: kids are watching their parents behave poorly on social media, and spend their time with their noses in devices. When parents of older kids still have trouble "adulting," that is bound to trickle down to the kids. Certainly, I don't look like my dad did in his late 40s, but I also have a pretty firm grasp of the responsibilities I have.

My kids also must avoid social media until they are 18. Heck, my older son had a feature phone until just two years ago, when he absolutely needed a smartphone for tools required for his position as a coxswain on his rowing team. Even then, he couldn't install apps, couldn't use a web browser. Since he turned 18, he's tried out some social media and other things, but mostly avoids them.