A friend told me that in competitive climbing people are required to be in isolation before the climb. As https://climbingbusinessjournal.com/strategies-to-help-youth... says:

"Communication in and out of Iso is always prohibited because someone could relay pictures of the competition routes for climbers to preview, resulting in an unfair advantage. Therefore, all electronics with internet connection are not allowed. An iPod without internet capability is allowed for warming up, but you are forbidden from listening to music while you are climbing the competition routes. I guess this sentence should be obvious, but no walkie talkies, cans on a string, smoke signals, etc."

There's also parents who get internet-free music devices for their kids. I've even heard of a kid who could take an old iPod Shuffle with them to a "no screen" camp, as it has no screen.