I like when you said "replacing oil and gas is not as easy as some people think" oil and gas is still very important infact it's plays an important role in human existence since it's a mineral resource however instead of replacing it totally there would be alternatives for instance there's fiat and there's Bitcoin, Bitcoin won't completely replace fiat but would serve as an alternative, that's how it would be concerning oil and gas and other energy resources in the future. That's why not everyone is buying the idea of electric cars currently cause they still believe that petroleum powered vehicles are still very useful, maybe in the future their use case would be minimal but they won't be completely eliminated.
For now fuel powered cars are considered more efficient compared to electric cars. But with time as more electric cars are produced which addresses the problems of electric cars previously manufactured, they will also be considered efficient. In start every new technology and invention has shortcoming that is fixed with time. Just compare computers we have in early 2000s to present straight of the art computers. Oil and gas still has it's importance specially in developing countries, which rely on it as fuel to run industries, vehicles and power houses.