Not that you’re wrong, but you could make the same complaints of any fuel source.

I'm not saying there's a perfect energy source (wind and solar come close but even they require some small amount of dirty manufacturing). What I'm referring to is the proportion of downsides. Hydrogen come with huge huge downsides, with very few upsides. In fact, I think hydrogen has only a SINGLE upside: it burns clean (no carbon).

Thats it though. Thats all. Every other measure its worse than every other mainstream electricity source, and its worse in much much larger proportions compared to other sources.

I read some interesting stuff about how Japan plan to create green hydrogen and convert it into ammonia to send through their existing gas infrastructure.

That does sound interesting, but its no hydrogen as a fuel source (like the article), its used in your description as a single link in a chain. So they're creating hydrogen from a process (likely electrolysis) using some other energy source, then nearly immediately converting that hydrogen into ammonia for better storage and transport. That would be a good use of hydrogen, as an intermediate step and not a beginning and end step.

Yes, the centralized nature of our energy grids are a problem. It's both a blessing and a curse. It's far easier to manage and makes investing in very expensive but very scalable energy generation systems feasible, but comes with the considerable downside that long distance power transmission includes all kinds of headaches and doesn't respond well to large shifts in demand. A very distributed system, say with some sort of neighborhood level power distribution/sharing system and per-house solar or wind power and storage would remove the need for long distance power transmission, but would be massively more complicated to manage, and still wouldn't solve all issues around large swings in demand, while introducing expensive ongoing maintenance (mostly in power storage). Ideally some kind of hybrid system where most power needs are met at the local level, with a few large systems to handle excess demand would probably be ideal, although then you're double paying for maintenance as you have to maintain both the local system and the large centralized one, but in theory the load on both would be more manageable. Unfortunately the current system is very much NOT setup to allow for local power generation and distribution and overhauling it to support something like that would be non-trivial.