Also, it's getting easier and easier to work, study and live for weeks without talking to anyone else than the grocery store clerk. I don't think that's a particularly good thing from a mental health perspective.

Talking with your mouth, or talking? Because it's not clear to me that talking online is significantly worse than talking in person at sustaining mental health. I suspect getting a girlfriend/boyfriend will do more for your mental health and social satisfaction than interacting with people face-to-face more.