Overall less efficient than electricity and is almost sidegrade to existing petrol, diesel or lpg. This video explains everything:
It would be a better idea to switch to ethanol before going full electric, as it burns on already existing engines and burns cleaner. It doesn't burn in all cars and is still somewhat sidegrade to typical fuels, but at least something would be done.
E85 is great on power but poor efficiency, worst of all it's highly corrosive to fuel pumps/lines.
There's a lot of talk about "all cars can run on ethanol", but if that were the case, E85 certification and fuel systems hardening wouldn't be necessary. The only people who actually use E85 are those who live a stone's throw away from a E85 gas station, people going to a race, and people testing out a new E85 tune on the dyno.
Then there's the whole debate about food vs. fuel and whether ethanol is actually tangibly better for the environment.
Given the amount of misinformation on Youtube, Documentaries, and overall the visual medium... I'd rather not watch a video.
If you have a legitimate point to make, you can find it in the written form of communication. Which is both easier to verify and easier to digest. There's still misinformation in blogs / articles / newspapers / whatever, but its much easier to evolve our ideas in the written form.
Donut definitely makes "for dummies" videos, but why not actually watch it before you write it off as being "just another misinformed Youtube video"? Pause on one of the overview frames and you'll pretty much get the gist of the video anyways.
TransLink (not to be confused with Translink in Ireland) used to operate a significant number of fuel cell buses in their fleet, coinciding with PR purposes duing the 2010 Olympics. All have since disappeared, while the other alternative fueled buses have not only lived on but are thriving (CNG, trolley electric, diesel-hybrid). They blamed it on high maintenance costs, and from what I can see there's not much reason to doubt that.
Notably, the vast majority of the articulated fleet handling the "B-lines" (basically the core commute lines) are diesel-electric now. The downtown core is served by a lot of trolleys, the smaller buses in the Vancouver region are mostly diesel, and once you venture out into the Fraser Valley you see more CNGs.
TransLink seems to believe that electric is the future, which makes sense as buses never require more than 250km range anyways, unlike semis; they've been sampling and testing various electric buses since about 2016. But it's a good demonstration of other factors preventing the adopting of H2 fuel cell in heavier vehicles. The tech is there and has been for a long time, but it doesn't always make for financially viable.
And H2 fuel cell buses don't necessarily have any more of an infrastructure burden than EV buses do. Yes, real estate is a bit of a luxury at a number of TransLink's bases, but to sustain their new LFSe buses they're going to have to build a shit ton of chargers all over the place.
Maybe semis will see a better case for H2 fuel cells, since they actually care about the range loss from EV and the performance loss from CNG. But that probably requires all the EV semis to flop spectacularly at the same time.