These concers exist for Hydrogen too. While the Hydrogen tanks can last a longe time, the catalyst in the Fuel cell degrades, like the electrodes of batteries do. That means that the fuel cell needs to be replaced as well after some time. In addtition to that, fuel cell vehicles need batteries as well, since the fuel cell is slow to respond to load changes. These smaller batteries are stressed heavily in stop and go traffic and will need to be replaced a lot more often than Ev batteries.