"Social pathology" is way too undefined a term for me to argue with.

I'm struggling to understand this one. Are you talking about the times of the cavemen, when I suppose everyone was equally materially poor? And yet you had other kinds of inequality back then, such as a bigger and stronger caveman being able to kill you and take your stuff, since there wasn't such a thing as a society or rule of law to protect you.

Or are you referring to the vast majority of people who for the vast majority of recorded history who lived in systems that elevated certain bloodlines above others, legally and culturally, and sometimes even to the status of gods? Certainly you cannot claim that, say, Queen Victoria and the common Englishman were more equal than King Charles is to his average subject, in every possible way.

For example, we generally take Forbes as an authority on who's rich, but really rich people tend to be excluded from consideration, because Forbes can only measure certain kinds of wealth, and even when people's wealth mostly exists in that form, it can be hard to see.

Don't confuse a convenience metric with actual inequality.