In the US there is a comparable work component. You are allowed to refuse any offer that isn't reasonable or comparable work. Sometimes you have to convince a judge, but there is an appeals process and so it isn't hard to argue that a bad job is beneath you.

Note that the above is about accepting a job. At times you may be required to fill out so many job applications (per week) and you are not allowed to refuse any interview offered. The result is people do apply for bad jobs and get an offer in the interview they have no intention of accepting.

Of course after a few months your benefits run out and then the low ball offer is more appealing as at least it gets you something. However even then a low ball offer isn't as common as you might think. Someone with no place to go will take it, but you cannot stop them from finding a new job next week. Offer someone too low and your risk they collect your money just long enough to become useful and then find a new job. You are paid for your first week of work even though you spend most of it learning and so you cost the company money in training, thus once a company hires you they need to keep you long enough for you to pay off that first week training time.

Note that in the US each state does things differently. The above is a generalization based on what I've seen in different states. The details are different and change.