I have a question about this. Why is this a good thing?
The issue is carbon. We extract it from the ground in the form of oil, we burn it, it releases to the atmosphere as CO2.
But if we take the oil and convert it to plastic, we have very effectively sequestered the carbon and it will essentially never be released into the atmosphere as CO2. As soon as you make the plastic biodegradable, the carbon will be released.
Seems to me, putting the carbon back into the earth is more responsible after we take it out of the earth.