Missiles do and will miss, due to many factors (from the missile itself losing tracking or counter measures, evasion..) and then from BVR the combat switches to close range. Proper engagement is needed to avoid jousting like a noob (and getting fragged by a more competent pilot).. It's true in today's world, and while space offer less terrain masking (we could make a case for asteroids...) there are still counter measures physical and electronic.That happens on earth now at least theoretically, I'm sure by Elites time frame missile tech will be preferred and killing people on the other side of solar systems.
Also having played DCS quite a lot i can tell that even in good conditions they are far from 100%..