Sounds more like underparenting, but at any rate I'm not sure you can expect noobs off the street to know how to conduct themselves in a horse barn, a learning curve you acknowledge with "everyone who spends a lot of time around horses is very aware."
As far as the disparity in phone usage goes, people with horses are doing an actual activity, improving their horse skills, and generally consuming their time with personal development. AKA "hobby," I guess! This is a luxury these days, especially if the regular horse people you see at the stables need rides to get there (99% of under-16s where I come from).
Lots of teens have parents who work too much, which puts horse activities on the "no chance" list. In this way, phones can be seen as a latch-key and support network for children and teens with (relatively) absentee parents. Now, not all of them are this way, but network effects work in IRL society too, not just on the internet.
As far as the disparity in phone usage goes, people with horses are doing an actual activity, improving their horse skills, and generally consuming their time with personal development. AKA "hobby," I guess! This is a luxury these days, especially if the regular horse people you see at the stables need rides to get there (99% of under-16s where I come from).
Lots of teens have parents who work too much, which puts horse activities on the "no chance" list. In this way, phones can be seen as a latch-key and support network for children and teens with (relatively) absentee parents. Now, not all of them are this way, but network effects work in IRL society too, not just on the internet.