There is a good book about this that discusses the problem you just mentioned [1]. Not only do we need to find a way to replace oil as energy source we also need to find a way to replace it in all the other consumables. Or at least find viable substitutes.

How this will happen is not very clear (to me)

[1] https://www.withouthotair.com/download.html

All the more reason to conserve oil for those purposes. It is too valuable to burn.

How much oil is used in manufacturing materials, though, rather than as energy? I suspect that's a small percentage.

About 12-13%, according to this: https://www.eia.gov/energyexplained/index.php?page=oil_home

And most of that is lubricants and plastics. I think we can all agree that reducing our use of plastics is generally a good thing overall - we might make the switch back to more easily recyclable materials, e.g. aluminum and glass, which, although energy intensive to recycle, are almost endlessly renewable.

Not sure what good substitutes for oil based lubricants would be.

The primary problem with petroleum is greenhouse gasses, so I'm far less concerned about its use in plastics than I am in its use for fuel.

I have low confidence in this answer, so I hope someone on the internet corrects me if I'm wrong.

Oil is refined into many different byproducts. Some of the byproducts are used in manufacturing, and other byproducts are used in energy generation.

Just curious, does drug manufacturing use up oil in significant quantities?

Also don't forget kerosine. Batteries are too heavy to lift.