Game balance in 3rd Edition was gone from the PHB onwards, out of like top 5-7 most broken classes in the game, 3 were in the PHB (Wizard, Cleric, Druid). A lot of stuff people consider broken (eg. Tome of Battle) isn't even really a power level boost for melee classes, just lets them in on the same move action + interesting option playstyle casters were doing since release (just at a much lower power level) vs. charge-> full attack full attack.

Not to say there wasn't broken shit in splats, but like half of broken nonsense was Core to begin with.