Don't laugh, someday a terrorist or hacker may engineer a fast-eating critter, and half our stuff will become useless in a year. Termites learned to work with gut microbes to speed up wood munching, a home-owner's biggest nightmare.
Some things, like wire coatings, will still likely need to be plastic and will become disposable. But most uses of plastic for long-lasting goods will just stop using plastics. Goods will get much heavier, but more durable.