I drove 1800 miles in a Hydrogen Car

The “why fuel cells” question makes no sense. Only someone who hasn’t considered it would ask that.
Because obviously not everyone wants to limit their driving to a short distance for the entire day and wait for charging. 
You can effectively keep status quo of driving and refueling quickly as needed, you can have more electric Uber/Lyft and delivery drivers, more electric vehicles on the road that are doing the actual hard mileage that will make an impact. For people who barely drive, battery is fine, but they were never going to make an impact anyway… people who spend 10hrs a day in a car seat will actually make a difference. Replace a couple hundred delivery vans and long haul trucks with fuel cell and you’ve already done a huge chunk of work.
If you have to ask “why” about an innovation, it obviously isn’t targeted at you… because you’d recognize the benefit immediately if it was.