>>14428331There are millions of different hydrocarbons and polymers like nylon are extremely stable molecules
It requires very sophisticated molecular machinery to break certain types of bonds. Perhaps the enzymes only required a single twist of an amino acid.
The entire reason there is so much coal and oil to begin with is because there were huge forests during the Carboniferous period that were not breaking down quickly at all in the conditions they grew in and they piled up and were buried
This is detailed in Isaiah 33.