So how would a "less abstract" Hide skill make the game more of an RPG?
In this specific case, it would (hopefully) help make the battles seem less of an abstract game and more like a fight where the thief is trying to sneak around in order to attack the enemy without being seen.
Another example of how this could be made less abstract would be to give the player a text description of what happened with several variations for different areas and monsters. For instance, a fight in a dark cave could describe the character throwing a rock to create a distraction noise and then hidin behind a stalagmite. Then, during the attack he could drop from an elevation sticking his dagger on his target.
Note that being more of an RPG can be a bad deal. For instance, making a game too much if a simulation can make playing it tedious or overly complicated. It could make badly affect the gameplay. All of that does have to be considered, but other things being equal, you want your game to have an internal logic as developed as possible.