I think that there’s a lot of value in NPC’s not doing irrational things just because of dice rolls. You might need a dice roll to convince them to do something crazy (get the guards to attack a dragon), but not for something normal (apprehend the thief).

I’m a big fan of passive perception too, where based on their scores some characters will notice stuff, and other characters will not. It’s certainly never as random as D&D makes it out to be, but I guess that’s kind of the charm. I just can’t stand it.