What about security? With so many interconnected vehicles accessible over the internet from different automakers, you know corners will be cut like the current wave of hackable petrol vehicles.
imagine a NotPetya infection/ransomware for autonomous vehicles: the doors lock, the vehicle speeds up to dangerous speeds and a screen or voice says “transfer 200 bitcoin here or we crash you into something/someone; you have 3 minutes.”.
Also on the economics front, petrol will still be in massive demand from global industries, like earthworks, shipping, trucking, aircraft and spaceflight. Not to mention all the plastics and other by products; though the prices may go up enough that consumer air-travel is no longer affordable..