I think that suggesting it's no different from people thinking that reading books was going to rot people's minds ignores the very real increases in teen depression, loneliness, and suicides over the past decade, as well as increases in adult depression and isolation, and the credible research that says that social media and screens are probably strongly contributing to it.
And really, even the historical sweating over pulp novels or TV addiction wasn't entirely unfounded.
If people are invited to spend tens of hours a week in soaking in media, that time is being borrowed from somewhere and in the modern historical context that's the time being stolen from home care, crafts and extra labor, sports and physical activity, third place social time in the community, etc -- changes that can dramatically alter society if taken up by enough people and can impact personal wellness even just for one person.
Constant, widespread social media immersion is absolutely having an impact on social and personal wellness and we can actually look to those previously normalized shifts as our evidence that it does.
What we aren't justified do, even as some here try, is assume that this impact of social media immersion will be harmless or beneficial just because pulp novels and couch potato living haven't yet destroyed modern society.
As you note, innocuous/harmless doesn't seem to be where the evidence is pointing so far.
Yes, I do not follow that argument comparing modern tech to past changes. It feels like people are assuming a weird technological inevitability. The printing press was amazing, it had a huge effect on society, of course, leading down the line to some kid reading trash in class. But it is just marks on paper, while digital technology forms a "place", and a direct line of effect from tech companies to the daily habits of billions of people, overnight. I think it is completely different...
Does that mean we should ignore teen depression, loneliness and suicides that happened in every 10 period before and pretend screentime is the cause.
Social isolation starts with kids not being allowed to play unsupervised. Don't hear too many cries to increase unsupervised time we hear the opposite. A screen might be the one thing to help that.
Jonathan Haidt has researched this topic extensively and concluded that it was both, or rather that it was the replacement of play-based childhood with screen-based childhood. Particularly social media's effect on young girls was very strong, but boys have been negatively impacted too.
Teen suicides went down when schools were closed at the beginning of the pandemic. They went back up when schools re-opened. https://www.nber.org/papers/w30795 I don't think teens were spending less time on "social media and screens" during this time.
That was basically my point but apparently I didn't make it clear enough - that we do and have had degradations, but they eventually become the new normal.
That may not be always bad, mind you, but it seems pretty obvious to me that it has occurred and is occurring.
I could rant much more about it, but suffice to say that just because we don't think something is a problem anymore doesn't mean it wasn't (and isn't) a problem.