Counterspin said:The wizard has always been broken because of his ability to outshine people at their roles, which is rooted in his huge flexibility. Slice him up, I say. I always preferred the subclasses anyway. Generalist wizards leave me uninterested.
Sure, but doing so is a waste of resources that can be used in places where there isn't another role to fill a need. Who else can create a wall of stone or teleport the party or create illusions or turn of the BBEG's magic? Why cast invisibility on yourself when casting it on the rogue makes him a cuisinart? Why cast stoneskin and tensers transformation on yourself when casting stoneskin on the fighter or barbarian lets him go nuts on the enemy.
I am going to go ahead and say with confidence that if you've sat at a table with a player whose wizard stole your fighter's or rogues thunder every time, you were all doing it wrong.