I am only joking a little bit here, but we only use the idea that “oil is the most reasonable energy source for civilization” because it’s how we bootstrapped our civilization.
Suppose there were some extremely stable and energetic combination of elements that was really easy to burn etc. we’d use it, but it’s extremely rare on earth. What if that is the result of the Silurians burning it all up 300m years ago or whatever - it’s rare because it’s been depleted already, leaving only the worthless and difficult to extract fossil fuels that we were forced to use.
This sort of discussion isn’t disimilar to SETI stuff - we look for water rich planets in the habitable zone because that’s what we grew up on - in reality we could be abnormal or rare-ish and has giant life or stuff living on Venus analogues could be the norm. We’re trying to make assertions from a point of informed ignorance - which is still ignorant.
I suspect (but don't quote me on this) that in the very big scheme of things our little fossil fuel addiction is just a fluke. Stars are such an endless source of high quality energy that the vast majority of "advanced" organizational forms ("life") surely figure out how to tap it rather quickly.
I guess the first question to your question is "what compounds fit that description". What processes could have concentrated them both to the point of economic usability and complete depletablity?
That's the hard question you're going to have to work around. Humans cannot 'use up' 100% of the oil/carbon resources on earth. It is energetically impossible for that to happen without turning over a significant portion of the Earths crust. There are always going to be signed of carbon concentrating processes on Earth, at least until our crust is completely remelted. This miracle energy source doesn't seem to exist anywhere now which would defy explanation.
Suppose there were some extremely stable and energetic combination of elements that was really easy to burn etc. we’d use it, but it’s extremely rare on earth. What if that is the result of the Silurians burning it all up 300m years ago or whatever - it’s rare because it’s been depleted already, leaving only the worthless and difficult to extract fossil fuels that we were forced to use.
This sort of discussion isn’t disimilar to SETI stuff - we look for water rich planets in the habitable zone because that’s what we grew up on - in reality we could be abnormal or rare-ish and has giant life or stuff living on Venus analogues could be the norm. We’re trying to make assertions from a point of informed ignorance - which is still ignorant.