alt Hacker NewsThe other apps are clients. The apps themselves don't actually contain any content, they're just code. An app that itself contains an offline copy of a book with NSFW text is not the same thing.
Meanwhile Reddit is a doubly poor example because even though the service contains NSFW content, it marks it as such, and then the client not only doesn't itself contain it but gives the user a separate opportunity to select against it when using the app to download pages.
Bible apps often don’t contain the text directly, but allow the user to download a preferred translation on initial startup. That didn’t prevent them from being marked NSFW.
And clearly that wasn’t the standard anyway. Before the introduction of the policy restricting religious texts, the only apps F-Droid had marked NSFW were frontends to porn sites, even though the apps presumably contained no sexual content directly.