Instead of slavery as a trope cop out it could have been a simple immigration system where you need an employer vouching for a person and taking responsibility for the person for a residence permit. This would make it a permanently voluntary thing, just find a new employer freely.
I understand and can reason with the concept of prisoner/criminal and I guess debt slavery (similar to imprisonment for debt which is a thing), it's something that somewhat makes sense in a historical setting where there's no proper state run prison system and there wouldn't be resources for it...
I love reading this shit to find out what preachy cringe bullshit the MC comes up with this time. I think this thing about celebrities loving their fans one almost tops it. Though the shit about the OL being harassed at the strip club was also very cringe.