Children are on Facebook because adults like you used their surveillance product and made them a "must have" aspect of social life.
Facebook and Google and the rest were harming society long before '20s. This was obvious to some us and when we spoke up forums like this were used to silence informed voices.
What about the less-tech-literate-than-us adult who tried their best to lock down the phone they gave their teen for "emergencies only", but the teen ended up hopping on social media anyway because of FOMO from their friends who were already there?
The kids feel the pressure from their own social circles, I can see it even with my littles and their requests for tablets and Minecraft at their young ages. And if they choose to give into that pressure in spite of their parent's best efforts, much of what they might use is designed to keep them there.
I made a comment about the petroleum industry's feedback loop making it hard for me to fully fault petroleum users for continuing to drive demand for oil in another comment in this chain. Like it or not, our society has become so structured around social media that we're already seeing something similar play out there. That feedback loop is driven by the companies at fault here.
We barely know the damage social media does yet, it's not comparable to taking the first hit of drugs at all.
Agreed that tech workers need to take a look at themselves too, but also it's the execs and governments more too blame.