Like hiring janitorial services instead of employing janitors, every decoupling of the system adds overhead. The people who could be recognized for being a good employee and offered other better positions are now often rigidly locked into low-wage labor permanently because no companies are willing to train people.
This is part of what is causing the rapidly rising inequality and college expenses. Many jobs that can be easily taught through apprenticeships and progressive responsibilities are being outsourced to colleges and universities, which were never meant to be all-encompassing career skills schools.
It also weakens companies' social contract, leading to even worse stewardship.