At first, I thought it would be a fairly down-to-earth depiction of slavery - handling luggage is the kind of a mundane thing you'd let a slave handle irl.
However, this place looks more like, pardon the comparison, an animal shelter whose inhabitants are hoping to get adopted to a good home. They seem to hang out in there voluntarily, could easily break out if they wanted, and have a strange sense of pride. Maybe serving a worthy master is a cultural or religious thing to them? The part where MC, a free man, is made to apologize to a slave with a deep bow is nuts.
By the way, they needed muscle for handling the magic stones, but bought two ordinary-looking girls? Hmm...
It would be nice to learn more about the slavery system there, seems like a boarding house.
Slavery wasn't always gulag-tier exploitation. In some cultures it was a relatively humane way of handling captives, debtors and criminals, who could even be freed and reintroduced into society through good service.
It actually bothers me that isekai slavery, despite being a perfectly legal enterprise and a source of extremely valuable companions, treats even the expensive 'merchandise' so poorly - starving, broken people piled up in cages like garbage.
...