‘Why wouldn’t you consider that to be the natural state of humanity?’
we are not born to servitude, are we...? we may be subjected to it, through weakness and timidity, and various other mental malfeasances, and yes, the historical state of mankind is the story of corrupted will to power and its imposed enforcement...but our natural will is to freedom, both of action and thought; subservience is anathema to our free wills, willing or otherwise...
I think that's very much an open question, especially if you eliminate religious revelation from the argument. (Religious revelation introduces points not revealed by pure observation.)
We are born helpless, utterly dependent on others for whom we can do nothing for years of our lives. If we are allowed to live, solely through the effort of others, do we not owe them some form of servitude, at least for a period of time, in exchange for our lives?
And on the other hand, some argue that it is parents, having inflicted life upon their children, who are in the position of being obligated to serve the children. "Why do I have to clean my room? You decided to have me!"