> Landfill space is not an important environmental problem. You should spend your worrying energy on something else.

Let me guess you're American, where free space is plenty? In most of Europe, space is constrained and about half the EU has banned ordinary landfills for that reason.

Also, landfills are an inherent danger to their surroundings in case the bottom barrier breaks and fluids seep into groundwater or that more-or-less uncontrollable fires break out.