When I point out that resources aren’t finite, people (the kind that is a peak oil alarmist) tends to respond something like “yeah, but it’s really expensive to create more resources”. Well, that is a completely different argument than saying that resources are finite. Finiteness implies a specific limit, not a vague difficulty to produce more. At that point they really admitted that resources aren’t finite, yet somehow they maintain that belief because resources are expensive to produce.
I agree with what you said about the difficulty of synthesizing oil, but oil is not finite. The theory that resources exist as a finite stock that gets ‘used up’ is meaningless and wrong. To understand resource economics we have to use proper theoretical models, and finite-earth theory is not accurate. In fact, it’s always wrong. I’m not saying that there is no problem with resources, but the problem is scarcity, not finiteness. Obviously resources will always be difficult to produce, that’s in the definition. Technology improves precisely because it keeps chasing scarcity. But lack of resources is not due to the overall stash on earth running out, but because supply can’t keep up with demand. I think we will get off oil, but not because we don’t have enough of it but because we find more efficient technologies. And keep in mind that oil reserves are growing, there is no immanent end of natural oil.