That is one of my favorite things to make with Alchemy. The Fortify Destruction potions can turn you into a God in under a heartbeat. Then, if you down a Fortify Restoration potion before the Fortify Destruction... the damage can go even higher.
Not using every weapon in the shed so-to-speak in regards to potions and other Schools of magick... well, that's kind of like a Warrior picking a fight, then putting his weapon away and going at it fisticuffs style.
Except a Warrior can do damage effectively within his
own primary damage tree. Melee and Ranged skills scale to +50% base attack damage, stacking and multiplying with another +100% damage via perks, and have an additional double-damage dealer that doesn't even require a perk. Is it more effective if you use Stealth, Smithing, Enchanting, and so on? Sure. Is it necessary? No.