That’s the sort of bullshit answer you take to Reddit, not HN.
Name the problems a battery half the size of a flatbed trailer "solves"?
That’s not half the size of a flatbed trailer and nobody with space for one trailer has real problems to solve that can be solved with a single delivery.
It’s cargo container size and that’s apparently a few MWH of battery these days.
I don't really understand this line of thought and where you're going with this or the point you're trying to make.