As was pointed out before, lack of literacy and a printing press didnt stop BG, IWD, or other games from having plenty of books with great world lore, history, and stories. The educated/rich would always have them, along with bookstores, in most worlds or history settings.
The books are mostly there for the player to read and enjoy, it doesnt have to mean that the character can read them. They could be found and enjoyed by the player, while being a piece of loot for the character.
There is also an interesting option with the PE magic being based on souls, as in-game 'reading' by illiterate PCs or NPCs could be achieved with magic 'writing' on books or items that could be understood by the souls and thus the person using it. Also, possibly being able to extract or copy knowledge, memories, and experiences onto books/items.
As for realism, in fantasy games I feel that after a certain point (where depends on the series/game) it stops becoming a good point and starts detracting from the game. Just because PE is being 'more' realistic doesnt mean it it cant include things that wouldnt happen in real life or have different levels of society development. This is a fantasy game with magic after all, not a game focused on hyper realistic detail and game-play.
Edit:
Also for lack of bookstores in a low literacy world, for the game it wouldnt necessarily HAVE to be a traditional bookstore, scribe shops would make more sense in low literacy world with no printing press, as they were around historically and sometimes had excess orders or common books in stock.
As was pointed out before, lack of literacy and a printing press didnt stop BG, IWD, or other games from having plenty of books with great world lore, history, and stories. The educated/rich would always have them, along with bookstores, in most worlds or history settings. The books are mostly there for the player to read and enjoy, it doesnt have to mean that the character can read them. They could be found and enjoyed by the player, while being a piece of loot for the character. There is also an interesting option with the PE magic being based on souls, as in-game 'reading' by illiterate PCs or NPCs could be achieved with magic 'writing' on books or items that could be understood by the souls and thus the person using it. Also, possibly being able to extract or copy knowledge, memories, and experiences onto books/items. As for realism, in fantasy games I feel that after a certain point (where depends on the series/game) it stops becoming a good point and starts detracting from the game. Just because PE is being 'more' realistic doesnt mean it it cant include things that wouldnt happen in real life or have different levels of society development. This is a fantasy game with magic after all, not a game focused on hyper realistic detail and game-play. Edit: Also for lack of bookstores in a low literacy world, for the game it wouldnt necessarily HAVE to be a traditional bookstore, scribe shops would make more sense in low literacy world with no printing press, as they were around historically and sometimes had excess orders or common books in stock.