There is a monetary compensation in most fields. Even though the PhD student might be bad, it is all his doing and choices, he can freely learn new skills and d

There is a monetary compensation in most fields. Even though the PhD student might be bad, it is all his doing and choices, he can freely learn new skills and develop himself. Even a horrible degree can lead to a comfy job. It depends on the field, in chemistry it looks like exploitation in engineering it's totally different. In art, languages, etc getting paid to learn is already a cherry on top.