I think this could pose a problem for truly awful jobs like at slaughterhouses, because nobody would be desperate.
I think this would pose a great solution for awful jobs: in order to attract workers you'd have to dramatically improve your working conditions.
Take Amazon's practice of hiring temps to work in their warehouses - Amazon might have to pay to introduce air conditioning and heating to their stockrooms, give their employees actual breaks, raise wages, etc.
Alternatively they'd invest more heavily in automation to replace employees, driving technological innovation while not displacing human labor.
Bit of a win/win.
It might drive up the price of meat until you could pay people enough to work in a slaughterhouse (or make it cost effective to automate them), but is that a bad thing?