I read a lot of inequality literature and news articles. The words that pop up the most are rent and rentier.
While it is only one part of the problem, the frequent mentions make sense because it is a standard economist way of describing how some people own things and earn an income from them, without actually putting any effort in. Getting richer from being rich.
While that is the current, real world equality issue, it rarely gets looked at in terms of the roots.
Philosophically nobody should own land – we all should have equal rights and access to it.
While in modern times a piece of paper says someone owns land, and despite it being legal and documented, if you go back far enough, that ownership was never legitimate.
Every colonised country, the land is stolen. At the time of colonisation, few if any countries had a concept of individual land ownership. Not only was their country stolen from them by force, an alien concept of an individual owning land was introduced.
In Europe etc, I doubt there is a single plot of land that was democratically allocated and has ever since been passed on by sale, gift or inheritance without dispute. All land “ownership” involves theft and wrongdoing at some stage, historically, and therefore all ownership of land is illegitimate.
Rentiers get richer from owning land they never had a right to, if you look back long enough. That makes things doubly wrong.