Over the last 40 years the trades also had influx of illegal immigrants entering the profession. These have been folks who were willing to do the very difficult work for less pay and no recourse if the conditions were unsafe.
Obviously not all trades as most firms won’t gamble using unlicensed electricians and plumbers. On the other hand roofing, drywall, concrete, etc... have been more readily given to folks who work for pennies on the dollar.
