Although... I have to say I haven't noticed spells being too powerful in this game.
That's because we're still at a fairly low level in EA. It's been a theme in D&D and related games for as long as I can remember, that mages start out very weak, but by the end of a campaign they're practically demigods in power. You try to keep them alive until the power curve kicks in.
I feel there's something fairly realistic about that pattern... maybe young mages are sensitive and more vulnerable to being beaten up by the tough other people - until they get really good with their sensitivity, at which point their way is vastly superior..
Also, about BG3 mages, I found their strength in this first act is primarily in their aoe spells - Burning Hands (whatever it's called), Shatter, Thunderwave. And who doesnt love a good Melf?