2 - the fiduciary duty of a company to its shareholders
3 - the desire of Americans of all classes for cheaper stuff
4 - our suffocating tort law system
In no particular order.
So you admit the middle class is all but dead on the floor. That’s good.
BTW, it seems you conveniently forgot another huge factor. It was government who opted to aid and abet an historic 30+ year endless flood of low wage foreign nations and illegal aliens into the job markets...And it continues as we speak.