What you are saying is they trying to screw you from the git go and not pay market wages. Yet they want loyalty and hard work. This is why snakes like Bernie Sanders even exist.
They are not necessarily trying to screw you, as you suggest.
If you want to hire someone to do some remodeling at your home, don’t you have a right to get several bids, then, using the info of the people you met and the cost assumptions they provided, YOU GET TO PICK which one you feel will be the best for the job? Maybe one of them has a slow time coming, and will do a quality job for less. Maybe one of them has been very busy on a big project, and will charge more.
The key here is that YOU GET TO SELECT the contractor that you employ. You are not forced by the government to pick the one that is charging “market rates”, just because there is some law.
This is the same for employers and employees.
Suppose you are doing a great job for the employer, and have some tremendous success with a project. Maybe the employer would consider paying a bonus, in appreciation. But now, the employer might feel that paying a bonus would not be within the “market value” for the job, so now you are screwed, due to the influence of the legislation.