Well to be fair, Melee classes are supposed to pull aggro away from Rangers, Mages and Summoners, hence why their end-game armor has the "enemies are more likely to target you" tag on it. Rangers on the other hand do NOT want everything focusing on them, nor do defensively bankrupt Mages and Summoners. To be fair though, it works out better in multiplayer than single player. Also, the two end-game ranged sets both have their disadvantages. Shroomite requires you to be perfectly still to maximize your damage potential, and against the Lunar Events, that's a bunch of deaths waiting to happen. At least Vortex addresses that problem by making it work at full strength even while moving, at the expense of moving slower, which again, during the Lunar Event or one of the Moon events, will kill dodging, something you absolutely NEED to have down pat as a Ranger.
So in a multiplayer environment, the melee user with Solar Flare or any other armor/accessories that pull enemy aggression can get many of the enemies to focus on him, allowing Rangers and Mages to attack in relative safety. It could also be a good synergy with a Mage using Spectre with the hood to heal the tank up while he draws enemy aggression and soaks up the damage with the Paladin's Shield. Naturally, Spectre Hood has been nerfed to near worthlessness (good luck hitting the wave 15 of a Pumpkin or Frost Moon with -40% magic damage in effect), but in a team setting, it could still be viable in that situation.
To me, here's how I feel:
Melee is spoon-fed at the start, but in general seems to fail at most bosses since most of them are out of your reach or otherwise hard to hit with melee weapons. This usually limits you to boomerangs, flails and yo-yos against bosses, since until you get projectile firing swords or a larger sword, you're not going to hit enemies easily. This seems to really be bad mid-game because have fun trying to kill The Twins or Skeletron Prime with a sword; you'll pretty much have to resort to Light Discs or a yo-yo to do any real damage given they're very anti-melee. End-game they get all kinds of weapons to overcome their lack of range, some of which frankly shouldn't be melee weapons (Daybreak). Also, Solar Flare armor really adds options for both tanking (-30% damage taken with the shield up at all) and the dash allows for good evasion. You're not a warrior or tank without it or its lesser alternative in Beetle Armor.
Ranged is viable early game and to be honest, when I get Corruption worlds, I usually farm materials to kill WoF as soon as possible using an Ebonwood Bow (alternatives being Iron or Lead Bow) and hiding under platforms while I kill Eaters with Flaming Arrows. Mid game it becomes essential for defeating the mechanical bosses, and the Megashark is the perfect weapon for The Twins and Skeletron Prime. Late game ranged becomes more reliant on evasive mastery due to average armor bonuses and lack of self-healing weapons. End-game they become insane; Phantasm or S.D.M.G anyone? Not to mention Vortex is a direct upgrade from Shroomite for set bonus.
Magic doesn't get much at the start other than a Wand of Sparking and if you get gems and ores fast enough, Gemstone Staves. Late pre-hardmode they really start to gain some good spells; Water Bolt being my favorite pre-HM weapon bar none. In Hardmode, their new spells are pretty easy to get (Crystal Storm being more or less a magic-based Megashark and Golden Shower for its debuff almost nothing is immune to). End-game they can either have good healing and awful damage with Spectre or overall higher DPS without self-healing. Of course, all that's out the window with full Nebula armor, and the end-game spells are crazy; Last Prism shreds the Destroyer in record time.
Summoning still feels like a gimmick class pre-Hardmode. The shame of it is that until you defeat Plantera and ideally get a Pygmy Staff, you won't be able to see a Summoner's true potential. Good luck beating Plantera with a nest of Spiders, a crew of Pirates or a swarm of The Twins that you won the respect of previously by the way. People complain about the awful defense of a Summoner, but that's not an issue since a Summoner can focus purely on evasion while everyone else has to aim AND dodge at the same time. It's just a shame Summoners have to wait 80% through the game's progression to at least become decent. Also, if you're doing a pure Summoner playthrough, have fun farming a Slime Staff with its 1 in 10,000 drop rate.