In D&D, mages always start disadvantaged in early levels but become very very powerful in the mid and late game.
In D&D probably, in BG3 they are the most powerful from level 1. Testing a solo wizard at the moment, and it's just horrendous how easy every fight is. The infinite long rests and their versatility is no match for every encounter in the game.
Something has to be done here because when the game releases, if it stands as it is, unless for romance purposes, I don't see why a wizard will need companions.