We mostly stopped using those "better" materials because people were poisoned because of their use. Lots more were poisoned or maimed in their production. And they were more expensive and more difficult to use and failure rates were much higher. And they were more prone to infestation by pests and molds.
Plastics are so much safer and cheaper and more reliable and easier to use that it's unreal.
Sources on the safety claims? Plastics were more flexible (in terms of usage), cheaper, and reduced use of paper and wood which, at the time, was a major concern as companies were clear cutting forests. Today, forestries follow sustainable practices. And while plastics are convenient (and in some cases a major benefit), there are plenty of areas where paper and other plant based products would still be just fine and worth it to reduce the harm that we now know plastics cause.
Plastics are so much safer and cheaper and more reliable and easier to use that it's unreal.