I first read about Hydrogen Fuel Cells several years ago. They sound really cool. Hydrogen and Oxygen go in, electricity and water and heat come out. A hydrogen fuel cell car is an electric car. It doesnt have a battery, instead it has a hydrogen tank and a fuel cell to convert it to electricity.
Unfortunately they havent really progressed since I first read about them. They are very expensive to make, because they need platinum and palladium for catalyst. The fuel cell and hydrogen tank are much more expensive than an equivalent battery. The fuel cell also has the problem of degrading over time and eventually needing replacement.
A big disadvantage of fuel cells is the overall efficiency of energy -> hydrogen -> motion is less than energy -> electricity -> battery -> motion. If the biggest reason to leave oil is the cost of energy, or the pollution from energy use then hydrogen fuel cells are a step down from battery electric vehicles.
Another disadvantage of fuel cells is they need an entirely new infrastructure for producing and distributing hydrogen. Electric vehicles have a large portion of the infrastructure they need, everyone has electricity to their house and workplace. Almost every place you need to go has electricity within 50 feet of where you want to be, they might need an upgrade in service or maybe just some wire.
The big advantage that fuel cells have over batteries is that you can refill a hydrogen tank much faster than you can recharge a battery.
If a hydrogen fuel cell car can make hydrogen while plugged in to an electric outlet and a water source, that would mitigate some of the infrastructure needed because you can do that at home. That makes it more like a BEV ( just a less efficient one ). Unfortunately the water would need to be distilled to remove contaminents or it would quickly poison the fuel cell, which would make it significantly less convenient.
If hydrogen fuel cells were magically cheap, magically a lot cheaper than batteries there would be an argument for them. Maybe they will be so much magically cheaper than batteries that we could pay for the more expensive hydrogen ( more expensive than the electricity to charge batteries ).
Then we would only need a hydrogen production system we dont have, and a hydrogen distribution system we dont have.
Its possible that hydrogen fuel cell cars will become practical in the future. I just dont see how anyone can think that they are closer to replacing gasoline cars than battery electric cars.
Electric cars are expensive, but available right now, many more will be available next year.
An electric car is completely practical and more convenient than gasoline right now for daily driving.
Electric cars can drive across country right now. Its not as convenient or as fast as burning gas because you have to use RV park infrastructure that isnt optimal for electric cars. But there is no evidence that a fuel cell car will be available for sale at any reasonable price any time soon, and there are almost zero places to fill up with hydrogen right now.