Oh I’ll save you the trouble: It’s not slavery, it’s just VERY shitty jobs for some of them, and specially a sense of “if you don’t get lucky in the DNA lotto, you’re lower caste scum”.
But I mean, here’s the thing, miners have children, those children get their chance with terrigenesis, if their mutations are not “good”, or non-existant, they go to the mines. BUT if they’re “good”, the kids get to do whatever the fuck else everyone does. I reckon that there are also other jobs… someone’s gotta make food, someone’s gotta repair toilets, etc, etc… My guess is everyone is sent to wherever their power can be used best, but because of overpopulation a lot of people end up at the mines. Tough shit, for sure, but it’s more of a situational thing, I reckon.
Maximus wants to abolish the caste system, yeah, but also get them all to earth… otherwise the whole thing wouldn’t work because of the outlying problem. Black Bolt on the other hand doesn’t want to go to earth yet, so he’s kinda forced to keep the status quo, rightly or wrongfully.
So yeah, there’s the potential for a really good story in there, buried under tons of cheap-ass production… =(