I don't think you are understanding the differences in scale. Ammonia is produced in truly massive quantities, it is one of the highest volume industrial chemicals produced. It is transported around the world in pipelines. The amount of hydrogen used to make steel is a rounding error by comparison.
Making hydrogen via electrolysis requires 50 MWh per ton. Manufacturing ammonia requires tens of millions of tons of hydrogen every year.
Right, about 40 megatons of hydrogen to produce all the nitrogen fertilizer. About 270GW average electrical power (67% HHV efficient hydrogen electrolysis, not counting liquefaction or compression).
BUT ammonia is a global commodity that can be and is distributed all over the world, so that means you can produce it wherever clean energy is cheapest. Chile has excellent wind AND excellent solar (best in the world), meaning you can operate electrolysis at higher capacity factor, and it has sea ports. So there are plans for big green ammonia projects being built there. https://renewablesnow.com/news/engie-enaex-plan-green-hydrog...
But it can also just provide food security by being a local source of fertilizer that is independent of global logistical constraints or fluctuations in availability of natural gas.
It’s also potentially an alternative mechanism for hydrogen storage. Some ships already run on ammonia, and you can run tractors (etc) on it as well without the extreme challenges in storage that compressed or liquid hydrogen have (its somewhere between LNG and propane when it comes to storage difficulty). However, it’s probably not a great consumer fuel due to toxicity.
Making hydrogen via electrolysis requires 50 MWh per ton. Manufacturing ammonia requires tens of millions of tons of hydrogen every year.