That's not the right analysis at all. Imagine if you did the same math for avgas in a world where some other fuel does 100 MJ/kg. You'd declare "We're not there yet to propel airplanes with avgas, not useful ones, anyway".

You don't have to outperform existing solutions to have a viable product. Price and other factors can easily swamp a particular performance stat. Different performance will lead to different use cases, but that is in no way the same as zero use cases.