I agree with what you're saying though, it would be cool to take something like those property owner layers and find the ultimate legal entity for stuff like LLCs owning land.
E, only semi-related: In the 'urban design' part of the internet I've seen really cool mapping that puts bar charts on top of a city's grid, with the bar charts being how much tax revenue the city generates. It's really stark to see skyscraper-sized bars in downtown cores and mostly flat all around where cities have zoned residential separate from commercial, or even where suburbs tax less than the core city.