Not all surveys, no. Just the ones where people have chosen to participate and are trusted to provide accurate information.

We know, individually, self selected surveys have problems with validity, as do self reported surveys. Combining the two is a huge problem.

What we can’t tell from this article at any rate is if it’s a failure in methodology or a failure in reporting. Either could be true.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5639921/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4115258/

That being said, there IS a more accurate way to define Apple usage among teens and that would be to survey the school districts.

“How many students do you have? How many devices connect to your network wirelessly? What percentage of those are iOS?”

That still wouldn’t be 100% accurate due to teachers and staff bringing their own devices, but the students vastly out number staff so the variance could calculated.