I don't know if this works for anyone other than our family but when we were raising our kids we solved this by the simple of expedient that gaming and computer use was done with us as parents present. Full stop. It was not a solo activity for our kids. We could directly view everything they were doing online the entire time.
Why would they? They grew up being 100% controlled with 0 privacy. They don't even know it doesn't have to be like that. Then, it was their parents violating their privacy, now it's government and corporations.