> A much more plausible causal explanation

Why is that much more plausible? It implies that it has always been there, and that nothing has changed since the last century, which is unlikely. Unless you want to introduce some other recent factor, but that is going to be even less likely.

And why? Because other studies have shown how addictive "phone" use is, and how it isolates people. And addicts (drugs, alcohol) are bad caretakers.

So there's really nothing that makes the explanation implausible.

You may ask yourself if it's not your own addiction speaking.