Is that a real problem here? Air filters on ICE cars are easy and not that frequent. You need cabin air filters regardless for passengers, so changing those at the same time isn’t that much different. Filters are cheap unless fuel cell ones are super expensive for some reason.

The air purity requirements for fuel cells are rather demanding. Impurities will destroy them.

ICE air filter would destroy them in no time.

Hm, I looked up how much a Toyota mirai filter is and they’re quite expensive. $270 it looks like from a 3rd party? It’s every 36k miles though. Not every year/12k like a normal air filters.

Yes, hydrogen cars clean the air as your drive them.