It was different for 1e fireballs, but for 5e fireballs, all equipment is undamaged as per the spell description in the Player’s Handbook: “It ignites flammable objects in the area that aren’t being worn or carried.” Aren’t means that this magically created fire does not act like modern incendiary ordnance in regarding scrolls, arrows, and other cool treasure. That makes it a lot easier to loot the bodies! That also means that wizards that are lucky enough to survive a fireball blast, both friendly and hostile, can’t be taken out of the fight simply because the spell-casting material components on their pouches have been destroyed by a fireball.