the only good builds are that with high damage with good sustain.
sustain = either or more than : defense, dmg reduction, lifesteal, evasion, block.
more useless class doesnt have that, example casters. magic casters do very little dmg compared to another builds, they usually dont have def or sustain to not get oneshotted. (some exceptions like light-cold sorc and magiczon, one has good def and another high hp, both have good sponge minions)
most melee class are useless, only viable ones are ones with insane defensive mechanics like paladin with blessed life and demiurge buff, dex melee classes like stormzon or sorceress with their high defense, leech and 75% block rate.
how to solve this:
- make late game dungeons less def-dependant, make ranged enemies to not run away when you get close, and more.
good for to achieve this: boost hp of enemies and lower dmg and attack rating/speed of enemies. dungeon maintain it's difficulty, but now are less oneshot mechanics.
buff magic casters: best caster equipment, buff dmg, and add some good ultimate to casters with life on kill mechanics, or dmg reduction. make more viable.
buff ranged characters : bowzon, bow druid are worst ranged classes. very low defense (later dungeons too def dependant). they have decent dmg but get oneshotted all the time on lvl120+ zones. they need to hit harder to be better glass cannons.
buff mele classes. more walking speed, more defense values or block mechanics to non-dex ones.
well that's my opinion.