>I hope you are not one of those crackpots who think oil comes from deep carbon deposits close to the centre of the earth, right?

No, I hope you are not one of those crackpots who think cheap, easily extractable oil is infinite, and that it doesn't get harder and more expensive (not only money, but energy-wise) to extract the more it is extracted.

>The consequence will be that we will be motivated to expand beyond this rock for more resources, which is a major advantage for humanity.

Do you know anything about planetary tipping points? The earth's climate could turn to something more resembling Mercury if we surpass certain warming tipping points, and same can be said regarding acidification of oceans, biodiversity reduction, and many other tipping points which, if surpassed, it'll be impossible to come back from, and we require as a species. The world and life in general could survive climate catastrophe, humans won't.