We can already make more land. See Dubai for example. And with AGI, I suspect we could rapidly get to space travel to other planets or more efficient use of our current land.
In fact I would say that one of the things that goes to values near zero would be land if AGI exists.
Perhaps but my mental model is humans will end up like landed gentry / aristos with robot servants to make stuff and will all want mansions with grounds, hence there will be a lot of land demand.