My dad in his mid 30s worked 13 hours a day + house work...he was a single parent back in 2011. There were no fixed weekends off. Sometimes, there would be a cool off season (heavy rain) but that's it. It was also pretty hard physical labor outside on a bike in 45C+ for hours in long summers. There was no AC or air cooler.
He earned $220 monthly as a salary after taxes. Of course, this was/is a small town and costs are not much but that was still pretty tight for a family of two - one of which was a small kid.
People at that stage don't complain anymore about work. They don't say anything at all about it. They just continue without speaking or showing any signs of burnout. The burnout may be realised for a short duration but afterwards, it's normal. I have done this comparison before and I think it still holds true. You are like a fighter jet or ambulance. Even if you are damaged, you can't stop and worry about it. There are people to look after or protect and without you, they will suffer. This is pretty counterproductive in practice. First, you will deteriorate your health and ignore any suggestions to improve short term issues. Second comes the switch from short term health problems to long term ones, this is a point of denial. At this point, those people stop caring about what happens to them and will dive even deeper.
I don't see my dad and think, "oh he looks like a slave". (Neither does he because he thinks it will pay off and he doesn't have time to be self aware of how much "slave" he is)
In any case, I feel slave is a pretty bad remark to describe a person.
I hope some people in the comments realise this.
I'll second this. It feels like you're always waiting for the other shoe to drop, or for you to be called out on not exercising the will-to-power hustle that the business culture of 2020 expects. A couple of slow months and I start getting paranoid.