Yes, bookshops will sell one version of the Bible to Catholics, another to Protestants, another to fundamentalists, another to progressives, etc. :)
In contrast, part of the SE editorial philosophy is that it tries to host the best (based on academic scholarship, translation quality, academic acclaim, etc.) version of each text available in the public domain, which excludes that "something for everyone" sort of play available to a commercial bookstore. You could rightly argue that this is losing something (it's good to have multiple translations to compare if you're reading a text for critical purposes), but the SE editorial philosophy avoids a certain amount of confusion and clutter for the general reader. So there's a deliberate (you could call it "arbitrary" in some sense, if you wish) tradeoff being made here.
US Barnes & Noble can have a few meters of shelves with different versions of the Bible, and a buying guide. It is quite striking if you are not used to it.
> So modern versions of e.g. the Bible could not be in Standard Ebooks.
There are modern translations that are permissively licensed and are of surprisingly high quality. See the NET Bible as a prime example. It's also the only one I know of with good translation notes that can be had for free.
One of the funny things about Bible translations is that more modern translations are based on older manuscripts than older translations, due to advances in archeology. SE can't carry any translations that incorporate the insights of the Dead Sea Scrolls, and having access to some of the oldest Hebrew manuscripts is a pretty big deal when it comes to translating the Tanakh.
It's true, modern versions of War and Peace can't be hosted at SE, but those modern versions generally don't reflect revolutionary leaps in archeology :)
In contrast, part of the SE editorial philosophy is that it tries to host the best (based on academic scholarship, translation quality, academic acclaim, etc.) version of each text available in the public domain, which excludes that "something for everyone" sort of play available to a commercial bookstore. You could rightly argue that this is losing something (it's good to have multiple translations to compare if you're reading a text for critical purposes), but the SE editorial philosophy avoids a certain amount of confusion and clutter for the general reader. So there's a deliberate (you could call it "arbitrary" in some sense, if you wish) tradeoff being made here.