I have that with software too, sometimes - again, due to lack of understanding. For most of my Java experience, Maven POM files for me were "that fucking pile of shitty XML I'm not touching with a ten foot pole, because it doesn't make sense". I didn't know why it looks the way it does, what any change will do, how to make anything work. I eventually bit the bullet and spent a day reading up on the docs and now I'm not afraid anymore. But it took me some years to first stop avoiding the topic altogether.
> 'losing all mail/photos/....' (which is, given the person's skills, usually actually very hard to do for them).
The thing is, they don't know that. They have no intuition for the range of operations and capabilities of a piece of software in front of them. You and I both know that this program they're using probably won't be able to find user's mail or photos by itself, much less delete anything - nor that anything in its operations comes close to deleting anything. But regular people don't know that, and I think the common factor here is not having an intuition about the limits of space you're moving in.