Why recycle, when we can leave it in landfill for future generations to find this valuable glass etc?

A bit of a tounge in cheek question, but with a semi serious undertone.
If most waste went into landfill, then in so many hundred years or so when such materials became so rare and processes to deal with this matter more efficient (say using solar power) I wonder if future generations would be delighted by our foresight that we had saved this glass etc for them to recycle and be thrilled to discover this treasure trove of raw material in the ground!