I'm sorry I am from a working class background and know plenty of skilled tradesmen. In good times they get enough work, in bad times they spend a lot of time on furlough. It simply isn't true that we need millions of more people in the trades, the supply is meeting demand just fine.
Actually many highly skilled trades were absolutely decimated by the collapse of American industry: machinists, tool and die makers, boiler makers, to say nothing of all those plant supervisors and other blue collar management positions.
And it can and probably will eventually happen to us digital tradesmen too.