In Path of Exile, poison is in a state where it needs immense passive investment and poe items investment to work. That means using nearly ALL the poison uniques with the exception of maybe the gloves (dendrobate, coralito’s, despair curse, embalmer’s in some cases).
Recently the volkuur’s lightning poison build has been pretty solid. Poison is in a fine place if you invest heavily enough. I think people are just generally used to the old double dip poison where you could play nearly any spell/attack + poison and it would be ridiculous. it’s still good, but far more limited in its applications and damage potential.
Poison builds can get really high amounts of damage yes, (got a mid/slightly high-tier investment build planned for 2.5mil shaper DPS) and outshine non poison, but it all depends on the build really. Also, if you have a chaos build and thinking of poison as extra damage, don’t, it’s definitely not worth it.
You can reach solid dps with poison but you are very limited with the gear. Also volkuurs guidance elemental poison is pretty much the only comfortable way to scale it atm, since you can get alot better dps with lower poison duration. But abyss jewels are the only thing that is making volkuur poison builds work atm. Worst part is ramping the dmg up for 5 seconds to start shining on bosses.
Poison is ok. Still a roughly 30% more multi on most builds. Which is not terrible and can match most 6th gem slot performance. Problem is that it takes 2 seconds to reach that deal the same damage as other supports are direct (no dot/time component). So in practice its a bit weaker than most supports VS bosses, and a LOT weaker everywhere else. That’s ignoring it not benefitting from crit multi.
It should be a top gem with effectively an 45-50% multiplier and be affected by crit multi (same as any other support..) to be worth using. Then you’d have these tradeoff of top sustained dps (poison) against burst (any other support). There is a very high damage poison build, using quill rain+ the coucil gloves(lighting can poison) stacking lightning jewels and wrath.
Hopefully the above guide will be helpful to you. If you do not want to lag behind others due to lack of orbs, there are poe items for sale on U4GM.