It's true — magic sucks. It demands way more investment, easily two or three times more, just to get the same results in survivability, damage, or versatility, compared to the other two viable builds in the game.
You're afraid of enemies, you need setups just to make things function properly, and by the time you finally start scaling when say around 30 WIS — surprise, surprise! You're still completely helpless against any boss or mobile enemy. Even a pack of wolves will tear you apart 80 times out of 100. You simply don’t want to play as a mage.
Yes, the sea witch exists, but in my personal experience, even in this case, there's little point in investing in WIS — you’ll be significantly stronger if you go down the right-side tree instead.
Overall, even after cheating myself the best possible wizard setup, I was left disappointed. The entire middle path is just a letdown