The trouble is, you are trying to cram an ever increasing amount of energy into those chemical bonds. You ned to get the energy denisty high to make it worthwhile. The more energy you put into the bonds the more unstable (Menaing fire or boom!) they are. Th research is to find the “sweet spot” where you got the highest possible energy and acceptable stability which means safety.
The question is: Will the physics\chemistry limit you in such a way that its never econmically viable with the right safety margin? That is no “sweet spot”. We will see!