Not following this thread but here is why Hydrogen is a pipe dream.
No step-change in tech is w/o engineering challenges. What is expensive in one era can become common not that much later in time.....living more than 2 decades, most people have experienced that process.
Many arguments (both sides, any issue) often exhibit Confirmation Bias........ but I'd put today's Net Zero debates towards the pinnacle of that list. Watched another vid recently, arguing for cramming more people in to cities, and expanding them...... conveniently ignores the Net Zero calculations involved with paving over adjacent farmland, and transporting more Ag products even further, to fuel these super-cities......
implementation/infrastructure challenges....... here or elsewhere, somebody cited a hydrogen filling station shut down because of problems/costs....... chuckling when I read that. Anybody who has worked with traditional infrastructure (ie. tech that is supposedly well understood) knows how typically under-funded maintenance is..... the people deciding budgets are typically bureaucrats and bean-counters, so it's no wonder a novel technology is exceeding "budgets".
I know of a Canadian city where the orders for EV buses have been halted. Not just due to issues with the buses, but it became inconveniently obvious that the way they were having to charge the existing buses was to have multiple very large (older emissions than existing diesel buses) diesel generators onsite, screaming away to rapidly charge the trial-fleet.
Major upgrades to the grid are $$$$$.....Who Knew ?

Most jurisdictions are way past the "Build It, We've got an Economy to Support" mentality of my childhood. So, in a lot of cases, all levels are waiting around to get somebody else to pay for grid upgrades......
Just a few examples....... turns out, if you actually still want to get Things Done (ie. Work), then hydrocarbons are not easily, and definitely not cheaply, replaced. I'm part way through it, if you can, get a hold of Fossil Future that came out this year, by Alex Epstein, I can recommend it.
While fuel-cells get attention, what is less discussed is burning Hydrogen directly. Burn it with air, and pretty much all you have to mitigate is NOx, which has been well understood for most of my life. Burn it with pure oxygen, and all you get is H20 out....... that I'd like to see in a water cracking pilot, fixed industrial use. Cake, Eat it, Get more Cake......
Hydrogen internal combustion engine vehicle - Wikipedia
I came across a great line from Peter Thiel....... paraphrasing slightly "Being extremely optimistic or extremely pessimistic (Things Will Always/Never Work Out) amounts to the Same Thing...... an Excuse to Do Nothing".
There won't be any one totally perfect replacement for hydrocarbons..... we just need to get on with implementing some improved alternatives,
that suit their intended applications......
Rgds, D.