I play a mage and many others do the same so...it has to be you not the game. It's single player after all, there is no need to do the most damage, have the most badass equipment etc.
I play a Mage as well, but only begrudgingly. Not because I'm actually having as much fun with it as I did in every previous TES game. There are so many things wrong with spells in this game it's pathetic, and the seies HAS turned into one that caters towards a meathead hack and slash style of play. I have an infinitely easier time on all of my physical characters compared to the caster.
And before the trolls reply with "Maybe playing a Mage just isn't for you", it's the class I've had as my first character in literally every RPG that allowed it and was never a problem until now.
In my opinion mages are almost fine, the real problem is smithing, enchanting and alchemy affecting melee too much. Melee is simply ridiculously overpowered if you max out those skills.
Yes, destruction might need some tweaking like scaling but that tweaking has already begun: http://www.skyrimnexus.com/downloads/file.php?id=611
I've tried this mod and it fits me perfectly. Once the Creation Kit is out, there will be much sophisticated fine tuning mods. What I would love to see in such a mod is a perk in Destruction which increases your damage by x% if you wear only cloth items because right now you don't gain anything from cloth as you can enchant light or heavy armor with -x% cost.
So relax, TES were always about modding. Once the Creatin Kit is out, all your problems will be solved.
Remove smithing, enchanting and alchemy for a bit. Know what? That doesn't improve Mages at all. Do you know why? Because the physical classes still have a much easier time thanks to weapon upgrades and skill increases. They won't be rushing to Daedric+++ items to blindly plow through the game, but they will still be steadily increasing from 1-50 or whatever. The way level scaling works in this game and because of how some elites seem to have ten times the health of trash enemies, it makes it much worse on someone who relies on a blue bar to deal all of their damage. The other problem is that the spells actually get more inefficient as you pickup the new versions. Sure, the cost drops as your destruction skill raises, but they are still less damage for the cost compared to previous spells. Then you have people saying "well lol all you need to do is powerlevel enchanting so that your spells cost nothing". So I should be forced to raise a crafting profession to it's max to make my damage tree viable? No physical class has to do this, and doing so with them just trivializes the game. You don't even need Enchanting/Alchemy on Adept level for physical classes to make it way too easy. Even on Expert, Smithing skill lvl 100 gear is way more than enough to easily plow through the game.
You are right about one thing though. It's up to the modders to make the game worthwhile in some areas. Although I would not go as far as to say it's as bad as Oblivion in any other area. I think Skyrim is pretty much everything Oblivion was lacking other than the magic system and some boring guilds/NPCs. I know people moan about the loss of the stats, but the functionality of them has been incorporated into your weapon skills. I loved screwing around, tailoring my STR/DEX etc like anyone else, but at the end of the day, unless you did something absurd, there was not really that much of a difference between higher level characters and it was all about gear and spells. And that's exactly how it is in this game.
Wrong. And guess what? There are more difficulties than Novice/Adept and some people keep playing the game past level 30.