> I’m super curious as to whether this technology completely destroys the middle class, or if everyone becomes better off because productivity is going to skyrocket.

Even if productivity skyrockets, why would anyone assume the dividends would be shared with the "destroy[ed] middle class"?

All indications will be this will end up like the China Shock: "I lost my middle class job, and all I got was the opportunity to buy flimsy pieces of crap from a dollar store." America lacks the ideological foundations for any other result, and the coming economic changes will likely make building those foundations even more difficult if not impossible.