Why doesnt trash decompose in a modern landfill?
Even with the (comparatively recent) advent of recycling, much of the waste that gets assigned to landfill is, indeed recyclable. This is partly because so many recycling plants are already operating at full capacity, or are governed by strict input / output quotients. Of course, despite what the governments of the world would have us believe, it is often cheaper to export waste to landfill sites abroad than it is to recycle it domestically.