I've been playing on Veteran with upscaling (consensus on that working appears mixed but I agree with the idea), at about level 7 right now, and I have been having a similar issue with debuff and damage spells on my wizard. In most engagements I have found myself looking through my spell choices for Aloth, I have all these great looking debuffs (confusion, expose vulnerabilities, the slowing one) but when I click on any of them and hover them over the enemies, they all have % to hit in the 30's and 40's. At that point I figure the spell isn't even worth the cast time and end up having my wizard shooting that frost warbow with the multiple projectiles for the whole fight.
Am I doing the wizard thing wrong or is this just the growing pains of lower levels? I really like the idea of the wizard laying down all these debuffs and area control spells to support the physical damage characters (never been a fan of straight blaster wizards since dnd) and would like to make it work.