The biggest thing for what plagues the net, society in general, did occurred in 2007 / 8 - it was not the phones - it was what the US govt did in response to Facebook's rather dire lack of real mods over "bullying" ... the move to ban anonymous people arguing and flaming - this flowed though eventually via the new terms of service US based software for forums, boards, and hosting sites required to abide by the new laws. Many forums I used to frequent slowly disappeared being unable to adapt to different software and hosting sites that were happy to ignore US laws.

A real name when challenging the status quo unfortunately attaches the risk of retaliation from either the intended organisation or person, or their fanboys, via direct or creative sets of problems designed to waste time and / or money. Sadly the internet is a bit more fuzzy when it comes to trouble and those dishing it out. Social media of course, had welcomed the new rules, and any anonymous account speaking out against a popular idea could be quickly reported and thus indirectly permanently banned until they complied with real life details.

I’m sorry, but this is such a terribly unscientific approach. You want to make a case for your hypothesis? Follow a structured approach with real arguments.

Saying «I know that correlation doesn’t imply causation», but then only demonstrating correlation isn’t really bringing this discourse any further.

You dont like margins on your web pages?

Not explicitly arguing against the thesis of the website, but showing trend lines which allegedly started in 2007 with data that starts in 2006 is... Not convincing.

Nodding along with the site until Fig 8. "Internet Addiction". If it has made up graphs like this with included the rest of the argument is likely made of false premises too.

Smartphones + Social media

And then COVID appears to have had a massive impact.

On September 26, 2006, Facebook opened to everyone at least 13 years old, was a key date IMO.