I think in the more nuanced view staffing agencies allow people with irregular rhythms to still have a job. And of course helping people actually get a foot in the door! But if you're going to work full time anyways, and there's more open-ness to you being hired, why go through a staffing agency? I think the reasons end up being limited to "could not get hired yourself".
Why would a person make $14.50/hour when they could make $15/hour applying directly to places?
The issue may be that so few people are looking for work right now that it's easier for convicted felons to be hired, perhaps not worrying about or taking on whatever vetting process that may or may not happen through an agency for people with a criminal record.
Yeah, the generally wouldn't, which is why you have to conclude that they don't have the option.
> maybe that negotiated difference leads to the profit slice
Of course.