Not sure.
I worked with a science team that had found very strong cognitive improvements in the short term (~2 weeks) after improving sleep quality. Though, study participants were mostly middle aged and elderly.
Is it harder to think clearly because you've just been watching shorts/reels for an hour? Absolutely not. It's an addictive waste of time, sure. But trying to claim some kind of cognitive impairment is just this generation's "X rots your brains" (where X has been TV and then video games).
1) a large enough group of actual close friends to use some social media app, so that by deleting that app you are removing a large part of your social life
2) those apps to continuously add infinite scroll, ad driven, engagement trap shit into every single aspect of the entire app.
Imagine if your work messages came through tiktok and by pressing back you were instantly dropped into an infinite scroll feed curated to your interests. Or say, slack gets bought and becomes an ad driven company who's only metric is increased time in app. But! Then your work refuses to change apps! So as you watch the app slowly become an attention pit, you are completely prevented from escaping it.
I don't think a lot of you old fogies really understand what the apps are like these days, or what teenage social life is like without the apps.
The fact that you're claiming that it's not harder to read an uninteresting paragraph after watching an infinite feed tells me you, luckily, have the privilege of not being tethered to these apps. You have the privilege to exist in a world where your social life isn't governed by ad revenue.
Because i grew up at the very start of all this, and some of my friends still use some of the apps, and everything that's "common knowledge" about phones and attention spans is true. The phone itself is fine, but i do think that the infinite scroll is just about the most dangerous device on the planet, barring the obvious ones.
This just reads like a thread about preventing teenagers from starting smoking, being filled with older people saying "why would you do that? Quitting smoking isn't hard, i smoked a pack once and was fine. And besides, smoking a cigarette or two doesn't hurt anyone, I'm fine".
In fact it's mostly the other way around. I watch them when I'm too exhausted to do something productive (which is often unfortunately).
I would agree, though, that improving sleep quality would definitely improve cognitive function.
But removing phones would only help if it’s degrading sleep. If phone addiction has no impact on sleep (e.g. the parents still enforce regular bedtimes), then I would not expect that much, if any, cognitive improvement. Not quickly, anyway.
Either way, these two need to be studied independently to know for sure.
They found that the kids' bed times were far earlier without phones, but was that a short term effect? Was it an effect of being observed and measured? If the parents valued their kids' sleep, why was the average bed time of 12 year old kids after 11pm pre-ban? You could blame that lack of sleep on phones if it made you feel better I suppose, but it's clearly not the whole story.