Hi,
its kinda cliche of many fantasy materials
Wizards are always old, wise, with white beard, have some sort of magic wand;
warriors have many scars, usually on places that are not critical, but where it shows both personality of character and the ways they fight;
e.g. scar over eye can be interpreted as metaphor of "character tries to watch all over surroundings and orient in fight, but if the fight gets intense, eye is the first that is hurt"; basically that warrior tries to use eye as battle weapon, so instead of damaged sword, his eye is damaged.
Elves are meant to be wise, cultural, more advanced race to humans, so their appearance, should suggest that.
That's why I think they are all clean, shaved, tall, noble, etc...
Being shaved suggests that they are cultural, they have other values than just fight; that they are intelligent.
Their height suggest that they are "above" humans, and so on, you get the point
But I agree, that's kinda overused.
If you are watching movie and some old man comes to scene, you know that he is smart and so on