Oil isn't just about fuel. What's that computer or phone you typed this on made out of? Generally not wood, clay or pure steel.

Aren't all of those things only a tiny fraction of our oil usage though? The entire global plastic industry accounts for < 5% of the oil we dig up IIRC. The vast majority is turned in to fuel.

Likely true. However that will need to last us a long time. 5% of oil is still a very large industry.

We could still make Polyethylene from renewable ethanol. However oil is more flexible, and if we do run out it's shit.

We make renewable ethanol from agricultural products entirely dependent on fossil fuels.

Yes, plastic is so passé.

That may eventually be true, but that just underlines that there are economic reasons to diversify whether or not you care about the environment.

The bottom line is these companies are being valued by the market based on the assumption that they'll be able to sell the barrels of oil in their proven reserves. If those reserves are "unburnable", the current valuations are not accurate, because the market for their product will be much smaller. Either they are valued correctly, or we're going to take action that prevents the worst effects of climate change - but it can't be both.

And also the present, and at least part of the future.