Eventually once we build the post-usefulness processing costs into products, we'll process/recycle everything fully as it should be instead of going to landfill; it's one of those Genuine Progress Index vs. GPD measurement things.
I think landfilling is pretty rare in developed countries. Mostly only the US has enough cheap free space to do it. Most countries incinerate their garbage. Countries that used to mostly landfill like the UK are now moving more and more to incineration.
