I think the idea is that if the infrastructure for hydrogen fuel exists and using fossil fuels is penalized, there’s an incentive to start producing more of it via electricity by, as an example, using excess power produced by renewable energy sources when demand is low, balancing the grid and leveling out electricity price fluctuations at the same time.

This relies on a lot of technical, economical, and political ifs though. The end goal is desirable but it’s not clear if there’s a feasible path there, considering the physical properties of hydrogen alone.