Back in the day when production activities surpassed in importance design, distribution and marketing, sure assembly line jobs paid quite nicely. Going forward, they will not.
Back in the day we in the USA built consumer products that were desired around the world.
Now we build and sell armament. Biggest armament dealer in the world. And because so many people want those guns, those factory workers make real good money.
So there is the difference. If, when we invent the next greatest thing that everyone needs (home fuel cells) or clean coal technology we could see a rebirth of assembly line work for some segments.
But I agree, millions of decent paying factory jobs are a thing of the past in all likelihood.
The one segment of the manufacturing industry that we ignore at real peril is letting our ability in the tool and die industry collapse.
We were the leader for years. No more. Not even close. Bad mistake.