What is the problem this visualization seeks to make obvious? Is it just neat to think about and make?

But I'm not a fan of these particular maps because the use of 3d makes them harder to read. The isometric view and rotation away from north at the top break conventions that people use to orient themselves in the map and connect it to their lived experiences on the ground. I'm reasonably familiar with NYC geography, and I could not immediately recognize the landscape I was looking at in these maps. Ironically, it was only because I already knew the answer to the question that I could do so: "oh that huge green spike must be Manhattan".

I think a 2d choropleth map with a diverging color scale centered on the mean value would work better.

Fwiw this sort of land value gradient has been studied in economics for ages. See papers on monocentric city model, going back to Alonso (1964), Muth (1969), and Mills (1967). Or even further back, von Thünen was talking back in 1826 about how land values spike as you get closer to the marketplace.