The real problem there though of course is that oil from the a well has always been cheating by not pricing in its externalities. To get an apples-to-apples comparison with synthetic fuel, fossil fuel would also have to be made at a minimum [0] carbon net neutral too, such as by running an atmospheric scrubber and ensuring that for every ton of carbon coming out of the ground a ton was getting captured again in an equivalently long term stable way.
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0: Fossil fuel extraction has always resulted in a ton of other externalities too, not just in terms of massive non-carbon pollution but geopolitical costs. That itself may well be a driver, if a country can switch fully to renewable/nuclear power and then run its entire economy solely off of that via grid/batteries/synthetic hydrocarbons the security implications alone are pretty massive. No more fossil fuel blackmail from hostile regimes, ever.
The problem is it costs a lot of energy, and so it ends up 4-5 times more expensive than oil from a well.