It's not really down to how tech savvy, it's more with being parent/child savvy. Top many parents use tech as a babysitter while the dangers are very real. Kids even younger than the numbers you posted above are allowed to run free on devices with no restrictions. There's many straight forward solutions ranging from so simply removing certain apps to putting controls on what kids can access and, probably more important, restricting the time they can use devices. There's lots of information for parents on, wait for it, the internet. It's too easy to say it's not easy. 

In the real world (not a dig) how many parents are as tech-savvy as their 13-15 year old offspring who have just been given a new mission in life?

One of a few reasons Robinson left.