> the value is all about how developed it is

If by "developed", you mean "built upon", that's empirically not the case:

Here's an empty lot in the heart of San Francisco for $2 million dollars: https://www.fortressofdoors.com/content/images/2021/08/image...

Here's a building next door to it on a similar sized lot for $2.3 million dollars: https://www.fortressofdoors.com/content/images/2021/08/image...

Location, Location, Location. The vast majority of the value of urban real estate is land (locational) value.