If you were a slave, you had to work hard, but Master took care of you (valuable property) and provided housing, food, medical care and always had work for you.
You forgot to mention, like a horse or a cow, the master had the right to sell you, your mate or your offspring. Rights the mine owner did not have. AS a slave, you would know that your circumstances would never change, that your children and your grandchildren would remain some one elses property. As a miner, you had the right to quit and move West if you could see your way to do that. You could see and work for a future where your children and grandchildren would have a better life than you, maybe even own the mine. This was a luxury the well treated slave never had. His children’s fate was already determined, they would live and die as someone elses property.
I certainly don’t disagree with your points.
My central point is that Plantation Slavery and the Welfare State have a lot in common. There are differences, of course. But there is a sense of being “owned” in both cases. There is also a sense being “taken cared of” in both cases. But of course being literally considered property is a uniquely bad status.
Free men like miners or mill workers had a better deal because they were free. But it was no walk in the park, they were not taken care of, and they had to shoulder a lot of responsibility. I would say that there are some segments of society that have just never grasped what a burden “responsibility” really is. Or they know and just can’t handle it.