There are other logistic companies that still have far better working conditions. So it is possible.
The whole construction of Hermes is made this way, that the conditions of the workers are bad and Hermes itself can wash their hands of it. Even the small companies in between this "chain of irresponsibility" are complaining of bad conditions and many go bankrupt for Otto's billions.
There are also contractors that admitted that they had to cheat the tax system to stay afloat. Many have gone bankrupt and the people involved are often left without social security. That's all inside the "System Hermes".