Except that oil is scarce to due to the laws of nature and that gives it it's price, whereas ether is artificially scarce. You could make a new piece of software called Blether that provided the exact same service and you could instantly 'double' the supply. Whereas with oil, you can't 'magic' your way into more of the resource by deploying some code.

Ether is not like oil at all. You only somewhat need ETH. Nothing stops you from using ETC. Or starting your own fork (either private or public). Your contracts will work there just fine.

On the other hand, it is not likely you can deploy some magic oil machine in your closet with almost 0 investments and start producing $5c / barrel oil.

Yeah, just like oil, except completely useless.

No... it's not like oil, or steel, or gold imo.

There's no way an economy can be defined by something of no practical value.

This analogy is not accurate.