The sibling comment from jeffbee is essentially correct, depending on which part of the "petroleum infrastructure" you're referring to in your comment: the price of extracting and burning fossil hydrocarbon fuels does not reflect the cost of their externalities, primarily climate change driven by CO2 emissions.
However, you are right in the sense that taking advantage of our current hydrocarbon distribution infrastructure would save capital costs versus switching to, e.g., an all-hydrogen or all-electric energy infrastructure. The trick is to get those hydrocarbons from non-fossil sources, which is a solved problem from a technical perspective but very much still unsolved from an economic perspective.
However, you are right in the sense that taking advantage of our current hydrocarbon distribution infrastructure would save capital costs versus switching to, e.g., an all-hydrogen or all-electric energy infrastructure. The trick is to get those hydrocarbons from non-fossil sources, which is a solved problem from a technical perspective but very much still unsolved from an economic perspective.