It's not catastrophic but it's not good.
Some classes like warlock, mage, druid or rogue need to put effort and create setups to get a kill and survive a teamfights while classes like shaman or paladin just need to run into the melee, spam frostshock and 2-tap everyone or spam self dispell and use HoF then auto-attack the target to death.
As for Warriors I don't know if they will get better with gear but it's easily the saddest class to see, I feel more threatened by hunter pets than warriors. Warlocks also look miserable to play with the number of paladins in bgs.