Hydrogen, like electricity and batteries, is an energy vector: you spend more energy producing that form than what you get from it.

Fossil fuels in general (maybe not shale oil) are sources, since you get more energy than what you spend. So, their energy return on energy invested (EROEI) is positive.

In this regard, we're facing diminishing returns, the low hanging fruit is long gone. This, plus resource scarcity, is going to be a huge limiting factor to growth…