I'm not certain I have either, but I'm also skeptical of blanket statements. Nothing, really, nothing? Do they have no imagination then? No value, no curiosity? ...or are these just difficult kids to manage in a room full of kids...?
> Do they have no imagination then? No value, no curiosity?
The opposite, but it doesn't mean the attention is held.
> ...or are these just difficult kids to manage in a room full of kids...?
If you remove "just", "to", and "of kids" then yes.
People—kids and adults—with severe ADHD struggle to manage in all sorts of rooms that others struggle dramatically less in, if they're undiagnosed and have no resources for dealing with it.
To me part of it is also that each generation intentionally seeks out what the last generation can't or won't fully adopt and adapt to. For the current generation it is AI. For my generation it was Wikipedia and online dating. It must certainly have seemed to our elders like we had little to no attention for the things they wished that we would devote our attention to.
If you look back through history, you don't suppose you might find a pattern of people saying, "Kids these days," do you?
Approximately nothing externally imposed will hold their attention, but ADHD hyperfocus is absolutely a thing: it's just hard to identify from the outside.