It might be even simplier than that. I wonder how much of an economy of scale effect we'd get from hydrogen production. For some processes such as refining petroleum, there's a big economy of scale. In those cases, it makes a lot of sense to have big refineries efficiently produce the products then to distribute them through pipelines, tanker trucks, etc.

However, what if there isn't such an economy of scale for hydrogen production? Suppose, for example, that production by electrolysis ends up costing pretty close to the same amount per unit volume at a small facility as it does at a big one. If, and this is just speculation on my part, this is true, then it might be practical to produce hydrogen in situ at the filling stations. Or, if that isn't practical, it might be possible to produce it locally at small plants just outside of town. Every town could have its own production facility, so there wouldn't be a need for a lot of pipelines and distribution infrastructure.

There is bound to be something published on this topic. I'll have to do some searching over the weekend.