Why should a fireball with 80 destruction hit harder than an arrow with 80 archery? Or are you saying you die far quicker than an archer in armor? In which case I would reply to you, that archer also has some sort of armor on (which just so happens to be a skill). Maybe level up your alteration and restoration if you're dieing so quickly. Armor/Health spells are just as good as armor/health pots.
How hard does an arrow with 80 archery hit? It depends on your bow and your craft skills. The Archery on my first character is only 70 but having 100 in smithing and enchanting... I have a Deadric bow with 53 Damage, 37 points of Fire Damage, 37 points of Frost Damage and using steel arrows for another I believe 12 points of damage... So each arrow is hitting for far more damage then the Expert Destruction spells with a skill level of 95 and it's easy to keep the bow charged, it has about 200 charges but with a soul trap/absorb stamina sword which has a damage rating of 188 when used with the full set of armor (2x+40 one-handed skill, total skill 180). Now I can enchant destruction cost reduction so all destruction spells are free but what is the point when I can instead enchant archery and do 3 times the damage with weightless steel arrows (which are insanely plentiful).
Now I have started a new character, a mage, I am starting to see more of the problem. I'm not quite there at the trouble marked area yet but I have seen some of the problem from my previous character too where destruction was leveled just for character levels more then anything. Mages can touch the OPness that Warrior, stealth and hybrid builds get but only via conjuration, not through destruction.
My Biggest Criticism with all spell schools is the Skill Level Perks, the half priced spells is only going to help if you start as a mage, else wise they can be ignored by just going for enchanting since enchanting can be used to get free spells in every school... you look at the combat skills, they all give +20% damage bonus for their base perk (which is the equiv of the magic schools skill perks). Also look at sneak with it's bonuses to sneak attacks, daggers can be made to do x15 backstab damage (x30 with dark brotherhood gear), which with Shadow Warrior can potentially allow you to chain instant death attacks which is very OPed only using all three craft skills is it possible to get more OPed then the damage of a single tree... mages get nothing like any of this.