You are ignoring the Surgeon General's report that connects isolation to mental health issues.
Not really. That report was largely about a decades long trend that has been developing for many, many years and as Twenge noted, the trends were about the same during the pandemic. You've cited her work as being an expert on this topic and now that she said something which went against your presumption, you're just going to ignore what she said?
You just want to blame for any negative statistic on the isolation aspect of the pandemic, and ignore the fact tat any of the current metrics could have been the same or possibly even worse without any restrictive measures which were implemented.