I am mostly pro-nuclear, and the comic is funny, but of course we extract energy from sugar, coal, fat, and gasoline via oxidation, while we extract energy from uranium via fission. So the more relevant variable being demonstrated in the comic is chemical process vs nuclear process, not how much energy is "in" the fuel. And that comparison is a lot less cut-and-dry.

Good luck getting fission to work on any of the other materials.