Headcanon: Due to their past, neither Zarya or Piper like sleeping on the ground.
When I first saw Piper’s bed, I didn’t think much of it. After all, Piper is very athletic and doesn’t think thing through, so I can see her thinking that a high bed looks cool. However, part of me wonders why that high of a bed interested Piper, and why no one talked Piper out of it despite clear drawbacks. This made me realize that Piper isn’t the only one with a bed off the ground.
Zarya has a hammock that she sleeps in. While this suits her tough personality and she’s likely not being used to an actual bed, a mattress on the ground or a sleeping bag would have fit to. It may have actually fit more, as a hammock requires places to hang it, where you could put a sleeping bag or mattress anywhere. Choko’s bed is also seen off the ground, as seen in “Game of Phones”.
I don’t think that either one’s just a coincidence. Considering how different the bedrooms are to each other, as well as the fact that we see Arkayna using her powers to decorate her room, I believe that they were able to design the rooms however they want. This makes me think that Zarya and Piper both have beds off the ground for a reason.
What I think is likely is that, wherever they lived before the stronghold, it was a bad idea to sleep on the ground. Whatever it is, I don’t think it damaged objects, as they don’t seem to mind objects on the ground. This ruled out flooding for me, as they would likely not want objects destroyed by water.
My best guess would be that some kind of bug often got in, and bites from it would have an adverse effect. If the bugs didn’t climb, then Zarya’s hammock would be safe, as the bugs wouldn’t have been able to climb on the walls/posts the hammock was attached to in order to get to Zarya. Objects would also be safe, as the bugs wouldn’t climb on them. They likely didn’t have actual beds, so they had to make do with what they had. So, Zarya and Piper got used to sleeping off the ground due to necessity, which carried over to the stronghold.











