I think we have to disagree there. Of course the details about what brings matter together, the opacity, etc, are important, just like anode/cathode design and

I think we have to disagree there. Of course the details about what brings matter together, the opacity, etc, are important, just like anode/cathode design and casing are important in batteries. Gravity's decisively not where the energy is coming from. Without fusion, stars would be cold, slowly cooling lumps of matter (or black holes, if there were no initial stars).