DMs, would you consider adding rogues/assasins as enemies against spellcaster who spam fireball? Or like a group of dwarfs with shield master? On one hand, it will encourage more variety in a future, on the other the spellcaster would feel bad that he cant do much in such a fight and would probably get killed quickly.
It doesnt feel right “punishing” a spellcaster who uses fireball as a solution to all his problems like that, right?
Edit: and make them tieflings as well…oh god…poor fireballers