Earlier quoted context omitted.
Here's an alternate interpretation: they're watching television now rather than movies. Because the kind of character development and depth of storytelling that can happen in 20 or 50 or 80 hours goes far beyond what you can do in 2 or 3. And the idea that young people can't watch long things due to a lack of attention goes directly against the evidence of the increasing habit of binge watching . Forget about watchin…
Great point, ultimately we're describing two different outcomes on where the current audience are spending their time on vs movies. You posit television series, if I could add to that list, it'd be live streams, YouTube, Discord, etc. All of these competing content genres are eroding the cultural cache and expected value of long film projects.
Serialized (as opposed to episodic) TV series are long film projects; crafted in ~10-hour chunks rather than ~2 hour ones.