There have been many debates on these forums about the best/worst classes. They have all been fairly inconclusive. Mages are powerful, yes, but warriors and melee rogues can pump out damage as well. Obviously having range is a huge advantage, as it is in every game in the world, but mages and archers need this range because they are squishy. Warriors can take hits, especially if they have a shield, and still have respectable damage output. I would say mages are only "better" than pure warriors and rogues because of the sheer variety they have. They get tons of CC, group attacks, buffs and debuffs, all of which can get really low cooldowns with high intelligence while warriors only have one skill tree and cannot reduce skill cooldowns. Battering Ram and Phoenix Dive are both powerful skills to close distance, and featherfalling a warrior into position can be effective as well.
Archers start off pretty weak, but they can start out-damaging a mage later in the game, especially against single targets. Also, arrows don't have to pass 2 tests. Regular auto-attacks are either hit or miss, and there is no resist (though armor can reduce damage). Special arrows are guaranteed to hit, but some of them can be resisted. And they just buffed special arrow damage (or at least some of them), so archers are even more effective now.
