Can someone give examples of the subject (not theories on or defense of the issue)?
The problem with a discussion like this is that many folks anecdotal evidence is often incomplete. This matters with references to things like play-style, campaign breadth, character choices, group dynamics, available rules supplements and so forth.
I've run several 3/3.5e campaigns. My main game ran for 6.5 years, running from 1st level to 28th level. We had 6 players consisting of a cleric, rogue, paladin, fighter (archer), wizard and first a second fighter (archer) who was later replaced by a druid. All characters eventually took prestige classes and most WotC supplements were adapted into the game.
Were the paladin and fighters outclassed by the wizard, cleric and druid at higher levels? The answer is a solid:
sometimes yes, sometimes no.
Example 1: The party and associated mounts, pets, cohorts and so forth are 17-18th level. In a desperate act, they seek out the enemy assaulting the town under their protection and discover that it is a Winter Wight (CR 23). It is arrogant, toying with them as blow upon blow misses, arrows fail to render harm, its wounds repair themselves and spells bounce off of him like spitballs. The party considers fleeing to avoid a TPK, as it's clear that the Wight could finish them off if it desired to do so. But then spell number 28, from the wizard, results in a natural '1', destroying the winter wight instantly, ending the combat...the only such roll that would allow it to fail a save. Neither the archer, rogue nor paladin could have accomplished such a feat. Combat ends.
Example 2: The party is 11th-12th level, travelling into the north. While camped out on a treacherous mountain pass, giants attack. Throwing boulders from up the pass at the cave the party has camped in, battle is enjoined. Rolling a boulder before them, the giants approach, using it as as a shield for cover. The wizard summons a massive illusion to distract them, then peppers them with spells from a long distance. The cleric, by comparison, makes stew around the campfire, feeding the equally bored rogue. The Paladin makes a show of standing in the cave entrance, but only one giant closes the gap. After the wizard destroys the boulder, the archers and wizard do horrible damage to them. Combat ends.
Example 3: The heroes are 21st level and facing a full-scale Githyanki invasion force. 250 gith fighters, two astral dreadnoughts, 10 dragon-riders gith knights, 20 gith group-leaders, 4 undead ghostly gith (CR20), 2 templated githyanki gish, 1 23rd level caster. End result? The druid uses flames to wipe out dozens of gith per round. The cleric decimates the super-gith ghosts. The wizard begins destroying things left and right. The paladin begins fighting the dragonriders in jousts. The rogue sneaks up on the casters and begins murdering them in earnest. The archer uses the benefits of range and magical powers to target enemies with unerring accuracy. Players force few survivors to retreat to the astral, where they will soon follow to find and kill the Githyanki Queen herself.
Example 4: The players are racing to free slaves from a mining colony and defeat an evil clockwork abomination and his extraplanar army. Archers drop the attackers at extreme range, but then the Bodaks arrive. Only the cleric has a chance to protect the party and stop them. When the devourer attacks, the paladin only barely escapes with his soul, until the cleric puts it down. The archers and rogue are totally ineffective aginst them.
The trend I've not discussed here (without going into massive detail) is that in each combat, terrain played a major part, ranged attackers were more effective and magic was a necessity. As the levels grew higher, magic was needed simply to survive (why did the cleric sit the battle out? Because he was loaded for bear with healing and restoration powers...but those aren't terribly useful in the middle of a fire-fight). Magic
could have been unbalancing if not for two things:
1.) I don't play with JERKS.
2.) The party worked as a team.
Through the majority of the game, each player could dominate in their category...though spell-casters had the opportunity to co-opt other roles if they put their minds to it....something the other characters could not. The cleric and wizard used things like Limited Wish or Miracle, but the Paladin set the game record for most damage dealt in one round (something like 230 points? I'd have to check the old story hour).
In all honesty, before I fully grasped 3e at high levels, the main threat to game balance was the archers, not the spellcasters. That's entirely my fault, though, and not the system's mistake. On the other hand, stories became much more challenging to write at first, with so many options placed in the players' hands by spells and magic items. I can see how some would run into this problem...and I think we had it happen some times.
But I can't say that it was a consistent problem for us. I worked hard to make sure that each character had their time to shine, melee and ranged fighters included.
