Random thought, but if we extrapolate the path we're on in terms of biodegradability and sustainability, it's not ridiculous to assume that a very advanced version of us would have developed the technology and legislation to ensure that all products biodegrade safely within X years.
Fair point, although not all of them, and not all of those that do remain. If styrofoam ever starts rotting, maybe the styro-philes will eat 100% of each cup and poop out only completely normal organic matter. Nobody will ever find it!
That is something, but apparently not quite what I want:
"Rinke and his colleagues are not suggesting that superworms should be released into landfills or polluted landscapes to munch through mountains of plastic"