I drove 1800 miles in a Hydrogen Car

First off, "show that you care"?  Just care dammit.  Let your actions speak for themselves.  I have one of the best energy conservation items you can have, a geothermal heat pump.  I don't have a sign on my lawn virtue signaling.  I simply enjoy the fact that  I use more than 50% less energy per square foot over basically anyone that doesn't have a GHP.  I enjoy it ethically, financially and even quality of life wise due to the fully climate controlled house that it gives me.

As for why fuel cells?  Easy answer.  Electric land vehicles, YES!  Batteries?  NOPE!  Batteries are fundamentally centuries old technology that are insanely resource intensive to make and don't last nearly as long as needed (Even the most recent batteries) and don't work particularly well in cold climates.  Fuel cells, regardless of the current question on the source of H2, are a far better overall choice for a whole range of things.  Homes off the grid, decentralized power grids and of course, ground transportation.  Tractor trailers and other massive diesel burning vehicles should ALL move to fuel cell configurations.  With them all replaced with fuel cell systems, that is a truly fantastic reduction in a seriously important source of pollution.  Diesel is TERRIBLE.  FAR worse than gasoline.