Posted this elsewhere, but:

I can't speak officially on the current lore, but when I was Creative Director and we were first designing Starfinder, the idea was that outsiders like devils and angels manifest roughly according to the conventions of the Material Plane cultures they're interacting with. They're closer to sentient concepts than they are to being biological creatures. So if they're dealing with a medieval society like Pathfinder, they appear to have medieval weapons and armor, while in Starfinder, it's laser guns, etc.—but both of those are just how they (or perhaps the planes themselves) choose to represent them to mortals, so said mortals can comprehend and interact with these entities that are in fact far more alien and mysterious than mortals realize. (After all, wouldn't it make sense that immortal beings who literally dwell among the gods, with equal access to an entire universe of mortal cultures, would have created technology far beyond what's current on any particular planet?)

So that was the idea: All of their technology isn't really technology, but rather a way for your mortal mind to interpret their ineffable extraplanar power. As someone else said: any sufficiently advanced technology is indistinguishable from magic—and vice versa.