Not entirely true; the disadvantage to land taxes is that they discourage prospecting and finding things like oil. You can ameliorate that in a number of ways, but land taxes aren't entirely without their problems.

That's an interesting point. And yes, it's entirely fixable.

At the most crude, you could separate natural resources from the rest of the land rights, people already do that.

By the way if memory serves right Germany, which doesn't have general land taxes, already doesn't let you own mineral resources below your land by default. Would be interesting to see what effect that regulation already has on people prospecting.