... which is still insanely wasteful because methane synthesis from scratch is just 50-60% efficient, and capacities are going to be limited - we need all the synth-fuel we can get for long distance air flight and transoceanic ships because these two usecases can't reasonably be shifted towards electric propulsion.

Making synth-methane just to burn it in a stove which loses a lot of heat to the environment compared to an induction stove.

[1] https://www.nature.com/articles/d42473-022-00166-2