It's been so long since I played I don't even remember what level Magic User you had to be to throw a fireball spell (although I do recall fireball and lightning were both 3rd level spells).
Fireball was a workhorse spell if ever there was. Typical scenario:
DM: you walk into the room and you see 6 hobgoblins looting bodies.
Player 1: "Ranger Rick" pulls out his +1 short bow
DM: roll initiative. [player rolls 6 and hobgobs 2]
Player 1: "Merlin" throws a fireball [rolls]everyone takes 22 damage!
DM: all the hobgoblins are dead.....