People are on their phones because the slop they are being served is so shallow and meaningless that they can't be bothered to pay attention to it
No, I’m pretty sure social media has seriously hurt the average person’s attention span.
The idea of sitting down and watching a two hour movie is really quite daunting when you’re used to videos that are at most 30 min and often less than one.
Whenever I watch a modern Netflix/Hulu/etc show: I'm on my phone 2 minutes into the show. Half paying attention to both.
Whenever I watch a modern BBC-ish (anything British really) show: I literally can't look away for more than 10 seconds because I will miss something crucial. If someone distracts me, I rewind the show and rewatch the last few minutes.
What's different? The Brits (at least the stuff that makes it into syndication) focus on content you're going to watch. The Americans focus on filling air between commercials.
Product placement counts as commercials for the purpose of this comparison.