I don't think that is a good comparison. Fossil fuel is a carbon sink. Extracting methane from fossil fuels in the ground releases the carbon from the sink and

I don't think that is a good comparison. Fossil fuel is a carbon sink. Extracting methane from fossil fuels in the ground releases the carbon from the sink and into the atmosphere. If synthesizing methane from hydrogen grabs carbon that is already present, it is carbon neutral.