Yes, it does. Second law. You need all of the energy that the fuel will store, plus more to run the process that creates it.
It’s conservation of energy, not second law.
Either you’re producing lower-energy fuel from higher-energy fuel, or you’re taking base constituents and available energy and synthesizing a higher-energy configuration.
High-energy fuel is simply fuel that allows to restore more energy per unit of weight. Take more low-energy fuel and convert it into less high-energy fuel.
It’s conservation of energy, not second law.
High-energy fuel is simply fuel that allows to restore more energy per unit of weight. Take more low-energy fuel and convert it into less high-energy fuel.