Lets say i want a daedric sword. If i level up smithing all the way:
-I level up quickly which in turn makes enemies harder
-i level up onehanded or whatever to increase how much damage i do to said enemies
-at this point i could probably just find a daedric sword.
I would almost be better off not investing into smithing and just leveling up basic trees.
Sometimes i feel like leveling is pointless. But anyway do you see what i mean?