A long time ago I remember hearing someone say something like “petrol is so useful that future generations will look back at us and say ‘they burnt it, who can believe that!'”
One of the obvious uses of petrol is to make plastics, and even with a change to a renewable economy plastics can still be made – but we need to do something with the waste plastic. Hopefully plastic (or similar) can be made fully and speedily biodegradable as there will soon be something like more plastic in the sea than living plankton. This is not good for anyone. A recent article suggested that even sea salt is polluted with plastic.
Plastic needs modification in the long run.