Is there a correlation between wealth and loneliness? I could definitely imagine it being effect for the poorest in society but I wouldn't be surprised if, once you've reached a threshold of being able to keep your head above water, money and loneliness had very little relationship if at all

Also being sufficiently poor. If you and everyone you know live off government assistance then that leaves plenty of time for social activities.

Yes Its about time. If you dont have time for your relationships they fade away.

So if you must work, thats lots of time not invested in your contacts.

There is. Middle class has it worst IIRC.