Nowadays, college graduates struggle for that sort of decent middle class life.
It looks an awful lot like the country, as a whole, is getting poorer.
As for your statement that "specific workers can suffer," what I've seen firsthand is that it's more like the entire local and regional economy, based on particular manufacturing industries, has been completely devastated. The area's basically been in a depression for multiple decades.
It's not so much about sending people to school for a few months or years to learn to do something else. It's more that, back when people who worked in the factories had money to burn, they spent it at a wide variety of secondary businesses in all kinds of different industries. Now the factories are mostly abandoned, rusting eyesores. A lot of the commercial real estate's gone downhill and is near rock bottom; people simply don't have money to spend on anything but necessities. The bad parts of town seem to be expanding, the drugs are getting bad, most of the ambitious kids and the people with money all pack up and leave for somewhere else. The closest thing to a growth industry is healthcare for the old folks who were born here and are going to stay here 'til they die.
The fabric of an entire community's been torn apart. I've seen it with my own eyes. Simply saying "specific workers can suffer" is a euphemism that minimizes, or even denies, the true extent of the damage.
#4: Economic disincentive for wealthy countries to fight wars with each other, leading to less dead workers on both sides.
Basically, for every unemployed worker in the USA, there's a Chinese worker who benefited. In addition there are new jobs in the USA (such as in entertainment or banking or information technology).
For this reason, both countries benefit in aggregate but if outcompeted workers fail to adjust to a different job, specific workers can suffer (like Mexican farmers suffered from NAFTA).
Economists favor free trade, but they also favor redistribution of some of the gains of trade to the losers (this redistribution hasn't been done historically).
http://www.igmchicago.org/surveys/china-us-trade
http://econlog.econlib.org/archives/2017/04/does_trade_with....