Well, with petroleum vehicles the infrastructure is all in place, with EVs it's partially in place through household outlets, so they have a bootstrap they can use to move up to public charging points. With hydrogen/oxygen vehicles there's zero infrastructure, so they'd be starting from scratch. That makes an already niche and expensive vehicle a *really* hard sell when customers know they'll be restricted to whatever area the car company is investing in to build filling stations. And of course that investment will have to be made. That's less of a problem for a warehouse since their vehicles only need to operate locally and they can built the electrolysis plant and storage tanks themselves. For a new warehouse it's probably no more expensive than building the battery charging stations or petroleum tanks they'd need anyhow. Another way hydrogen/oxygen vehicles are gaining a foothold is though public transport. Busses and trams follow specific known routes and always refuel at centralised depots, so they can simply build the refuelling plant there and know they'll never need anything outside of that. Conceivably the tech could spread from there to taxis and eventually commuter cars using the bus depots as a jumping off point. The other issue is subsidies: EVs are flavour of the month with environmentalists, so they get all the funding. And the EV industry is established now so they can afford to outlobby any nascent fuel cell ventures that might compete with them.