But we need to separate scams from what is under discussion here.
The Great Salad Oil Swindle is interesting reading too. Apollo fuel cells worked. The technology works.
Why isn’t it utilized?
It all comes down to cost. Fuel cells, at current level of development, does not return your initial investment at a sufficient level to be worth investing into it.
FL
For something to be worth buying into, you need your money back in a reasonable length of time.
Fuel cells may have been the cheapest option or even the only viable in space. They aren’t on earth. They couldn’t compete.