Development of surrounding land increases land value yes, but the idea is that since the landowner didn’t do that development themselves, they shouldn’t be able to profit from it through increased value of their own land. “Land value” is kind of an amorphous though, another way to think about it is that we want to incentivize the most economically optimal use of land in high demand areas, thus we should tax all land proportional to demand (measured via price) to encourage those landowners who have undeveloped or under-utilized land relative to demand to use it.

(note this is counter-intuitively pro-environmental because it applies most to land with high demand, e.g. cities, not forest or farmland, and if cities can be successfully densified to satisfy housing demand, pressure to sprawl can be reduced, increasing those lands left to nature)

We need a land value tax to stop real estate speculation.

LAND VALUE TAX