I think the main reason for the 3D is the scare factor. In 3D the oppressing nature of the dungeon with monster sounds is much better, and you get the “monster jumped you from the side” element. Scary 2D games require blacking out most of the screen and rather costly light effects.
Btw that plate part, later in the game it’s a good sport to revisit the place and just wreck all of the trapped monsters.
Also, if you move your mouse to the very bottom of the 3D view, the arrow changes and you can look down (same goes for up). I found navigating the maze easier that way.
