Keep in going down layer after layer and you’ll ultimatelly find it’s all ownership claims on limited resources and the products made from such resources and trillions of man hours of work (which in turn also boils down to the resource which is “time”, specifically “fractions of human life”).

Also there’s quite a lot of things directly and indirectly owned that whilst abstract and naturaly infinite, were made scarce by Laws, such as copyrighted materials (which could otherwise be freely duplicated) or brands who are only worth something due to trademark (as otherwise anybody could use any brand mark, so brand marks would have no recognition or trust value).