Paraphrasing my doctor: infections have evolved to the point the fever isn’t effectively contributing to fighting the infection, but we never evolved to stop making the fever. Since it doesn’t do us any good, we might as well be as comfortable as possible while our immune system does it’s part.
Cheapest oil runs out in x years. Mid cost in y years. Expensive in z years. Then we get into “manufactured” oils.
Oil isn’t going to run out, it’s just going to get more expensive.