Serious question: if somebody knows that a job like this is such a ripoff (even if the rates aren't advertised, you _will_ find out soon enough, if via stories like this), why would somebody take a job like this?
Unfortunately, in this economy, it's probably more accurate to say "most people really don't have options" rather than "some"
So while it's a 'strong market' in the sense that 'unemployment is low', it could also be examined from another angle. Which is the rise of the gig economy giving people a lot of opportunities for work, but work that comes at a cost of being heavily exploited like with Instacart. Nor does it say anything about whether or not people are holding full time vs part time jobs or the stagnant wage issues.
When you have a felony a lot of higher-paying unskilled jobs will simply filter you out as being too high risk or likely to cause trouble. So the only places that will hire these kinds of people can get away with crazy tactics like the ones people are discussing in these threads. When your choice is exploitative tactics or literally no other option because the entire market has you blacklisted you are going to take the horrible option knowing full well it is a horrible option.
For some people though there just aren't a lot of jobs available that match their education and experience.
People that are desperate for money are frequently exploited. Whether it's through wage theft, or unsafe employment practices, or simply demeaning behavior.