I don’t think oil is going anywhere any time soon. Even if vehicles were suddenly completely electric in 20 years and all power generation no longer required fossil fuels, we still have things like jet fuel, asphalt, and plastics that require petroleum.
Not saying the saudis aren’t forward thinking about what to do when demand decreases, but so many folks do believe that oil = cars and going electric means we don’t need oil.
You start to diversify 30 or 40 years before the catastrophe. If they wait for oil to be valueless before investing in anything else, they will discover they don't have anything of value to invest anymore.
All of which sum to significantly less than current demand when used for ground transportation and heating/cooling. Would not be surprised if this followed the 80/20 rule.
Not saying the saudis aren’t forward thinking about what to do when demand decreases, but so many folks do believe that oil = cars and going electric means we don’t need oil.