Myself, I think like a lot of people on this website, grew up with basically unfettered access to the internet and computers. And that period of time today seems like a golden age of the Internet. Maybe you think the internet today is just so insidiously dangerous compared to them, but I think that's just naive. The internet had a lot of fucked up content when I was accessing it at that age too. Our kids are going to grow up thinking the time they used the internet as a teen was the golden age.
I'm not saying unfettered access is what you should do, but maybe imagine yourself in your kids shoes, only it was the 90s with home computers instead of the 2000s with apps and social media?
You may have great arguments about the net harm of social media or apps you don't happen to like, but they are not going to resonate with your kids if you approach it via "I know better then you." If you're on this forum, you are very capable of setting up home wifi that you can monitor. Why not see what's a problem for them first and address it then?