I’m thinking Dwarven step pyramids would serve a different purpose than they did for the Mesoamericans.
For one thing, they’d be built in such a way as to be visual homages to certain specific mountain ranges. That would mean some would be adjoining.
And they might just be “regular buildings”- dwellings, workshops, and yes, granaries.
I’d imagine that some would even be used like yakhchāls- ancient buildings constructed in such a way as to store and even make ice…in deserts. And similar building techniques would mean the Dwarven pyramids intended for use as dwellings could be “air conditioned”.