I think this is an important and often overlooked phenomenon actually. Studies of Internet engagement are filled with these skewed distributions that follow something like a Pareto principle, or I've heard it termed the 90-9-1 distribution in engagement where 90% of users just lurk a bit, 9% contribute casually, and then 1% are contributing like half of the content on the platform.

It would follow logically that whatever kind of brain rot social media causes, would affect 1% of the population very dramatically, another 9% somewhat more noticeably, and then there would be this vast ocean of people who are only marginally aware/affected. From the perspective of online activity they appear to not even exist.

This always seems counterintuitive to the 9% or the 1% (and just by commenting we're already in one of those demogs). But there's lots of data out there supporting these skewed distributions in online activity.