In Early Hardmode mage weapons are actually pretty decent but the armours aren't insanely good yet not bad (though melee and ranged use those armours too), in late Hardmode (post-Plantera) the weapons are awesome and Spectre Armour is alright (but the hood is useless against ML), however in Pre-Hardmode there aren't many (or very good) options until the dungeon apart from the Meteor gear. Pre-EoC there's just the Gem Staves which aren't very powerful or interesting, the Thunder Zapper which is basically just a Gem Staff with squiggly projectiles and is sorta hard to get, the Wand of Sparking (which nobody would obviously use) and the Demon Scythe which is hard to get and awkward to use. At that stage for Melee there's all the swords, the flails, yoyos, the spears, etc., for Ranger there's a bunch of the bows and guns (not much variety but lots of options nonetheless), and for Summoner... well, there are very little options, but the Flinx Staff and the Vampire Frog Staff are good. So I think with the exception of pre-boss mage is fine as a class.