Polystyrene is a semi-natural product It was discovered/invented in 1839, as an oily substance distilled from the resin of the Oriental Sweet-gum tree. It was not just tree resin, but a resin that had been processed by distillation.
Not till over a century later, in 1944, was that the distilled resin was turned into foam, soon known as Styrofoam. This was still the same chemical product, but expanded to include 98% air.
Sytrofoam/Polystyrene proved very useful for packing and transportation. It was extremely light, so added little cost to transport that charges by weight. And it was soft enough to absorb most impacts, meaning that it could protect reasonably delicate equipment.
The downside of polystyrene was the environmental impact. even though it derive from tree sap the product was not organic, and it took decades, if not centuries, to break down. So polystyrene stayed in the environment, where it was a hazard to sea-life and wildlife if consumed, and generally taking up a lot of space.
But there are ways to deal with polystyrene.
IS recycling machines can greatly reduce the bulk of polystyrene, simply by compressing and removing the air. The machine processed polystyrene takes up far less space than regular foam polystyrene, so it is easy to transport.
The polystyrene can be turned into building material or plastic products like cutlery.