Switch from "national level" tab to "metro level", and select los angeles for an extreme example. Look at the the figures right of the map, that says "share of SFD units build before 1980 with a land share of" and compare the figures between 2012 and 2024. Just by eyeballing the percentages, it looks like the land share went from 50-60% to 70-80%. This is confirmed if you sum up the figures in a spreadsheet, you go from an average share of 51% to 72%.

You can compare this to overall housing prices in the LA area[1], prices in 2024 is 262.7% of 2012 prices. Suppose you have a $100k house in 2012, that will worth $262k in 2024, an appreciation of $162k. Using the land value percentages above, the land value of the houses are $51k and $188k respectively, an appreciation of $137k. That means 85% of the appreciation was in land, not because building materials got more expensive or whatever.

[1] https://fred.stlouisfed.org/series/LXXRSA