I have read everything you just wrote. Yes you are right that a mage can not just take destruction, and only destruction and be viable. No one was saying that.
Using alchemy to improve the damage your spells do is fine and dandy, but you shouldn't be chugging them on EVERY FIGHT.
What I am trying so very hard to do, is to get people to understand this one little thing. Destruction magic, a school of magic who's only purpose is to deal damage, thats IT, isn't the most damage dealing magic. Its as if heavy armor was less protecting than light armor, which is absurd (assuming both were equal in perks). It just should not be. Destruction should do more damage than twin dremoras at 100 destruction because the dremoras do damage, distract enemies, and act as tanks. Destruction magic does damage, end of story. Destruction magic should do more damage than 100 illusion, but no, I can frenzy the "boss" of the room so to speak, and he'll clear it out for me, leaving himself heavily wounded in the process, and thus, easy pickings. I just want destruction magic to be as effective as the other schools considering how much magicka the spells cost.
Diebysword, read this part of the post. Note the bold, italicized, and underlined part:
Now, let's jump to the endgame, and no enchantments(single skill only.)
One handed Mastery Weapon Stats(All Perks): Daedric Sword x2 (100 damage per hit, 300 damage per power strike, power strikes now take 75% of previous stamina and stamina meter is much larger. Assume 500 stamina(most points into stamina) Assume 10 power strikes before depleted: Total damage before depletion: 3000 damage, then damage drops to 100 damage per second)
Destruction Mastery Spell Stats(All perks): Lightning Storm Dual Casting (112.5 damage per second, 59 magicka per second. Assume 500 magicka(most points into magicka), lasts for about 10 seconds, for 1125 damage. Magicka regenerates at 3% per second, base, resulting in 28.125 damage per second once magicka is depleted.)