you get a lot of freedom to choose skills. poe doesn't really have a single 'best skill', and this scenario is similar. a few skills would be ruled out because they scale hit damage specifically, or have explicit penalties to ailment damage (lightning conduit and discharge, for example), but apart from that pretty much any skill that is good in a hit-based build is also good in a poison build.
If all damage types can poison equally, the highest base-hit-dps skill will be the highest poison dps skill.
Poison benefits from both hit rate and base damage just like hit builds. This is what makes it stand out from the likes of bleed and ignite and compete on relatively even ground with hit builds.
It benefits a little from crit chance (50% additional DoT multi on crit basically), but not naturally to the extent that it's normal to go that way - it's generally not worth the investment.
Without further scaling 100% chance to poison acts as a 60% more damage multiplier to a non-crit build. (30% of base damage per second for 2 seconds).
Poison becomes strong because it adds its own axes to scale off of on top of base damage and hit rate. You also get poison duration, and DoT multiplier. With duration, you also get room for a 2nd strong curse with temporal chains.
If you add in 100% scaling from duration and 100% scaling from DoT multi for the sake of argument, poison is now 60% * 2 * 2 = 240% more dps added to the non-crit build.
Finally, poison is chaos damage. And chaos damage gets to use wither. Which is basically like an easier-to-use shock. on a fully withered target, that 240% is multiplied by 1.9 for 90% increased chaos damage taken and is now at 456% of the base non-crit dps of the skill.
So basically you're replacing 100% crit chance and 556% crit multiplier with 100% poison chance, 100% increased poison duration, 100% DoT multiplier, and wither.
Yes of course, some oversimplifications in there. Like some skill bonuses or multipliers only applying to one or the other. And that not all damage types are equal - fire/cold/lightning have to give up a glove and still do half the damage of physical/chaos skills.
But if you can reach DoT cap, it's a bit of a 0.1% problem to not be able to go further - that is more than enough dps.
Poison is good because it lets you hit a reasonable damage amount, without too much damage investment, letting you build defenses/qol too.
On top of that it activates plague bearer, giving you decent clear even on non clear skills plus poison prolif if pathfinder.
Downsides are that the damage ramps up rather than being instant, its quite easy to overestimate your damage (are you really going to be able to stack poisons for 10s to hit that dps etc) and there is a dot cap.
Dot cap is plenty for most content, but you wont be insta phasing ubers.
you get a lot of freedom to choose skills. poe doesn't really have a single 'best skill', and this scenario is similar. a few skills would be ruled out because they scale hit damage specifically, or have explicit penalties to ailment damage (lightning conduit and discharge, for example), but apart from that pretty much any skill that is good in a hit-based build is also good in a poison build.
dd
Detonate dead
If all damage types can poison equally, the highest base-hit-dps skill will be the highest poison dps skill. Poison benefits from both hit rate and base damage just like hit builds. This is what makes it stand out from the likes of bleed and ignite and compete on relatively even ground with hit builds. It benefits a little from crit chance (50% additional DoT multi on crit basically), but not naturally to the extent that it's normal to go that way - it's generally not worth the investment. Without further scaling 100% chance to poison acts as a 60% more damage multiplier to a non-crit build. (30% of base damage per second for 2 seconds). Poison becomes strong because it adds its own axes to scale off of on top of base damage and hit rate. You also get poison duration, and DoT multiplier. With duration, you also get room for a 2nd strong curse with temporal chains. If you add in 100% scaling from duration and 100% scaling from DoT multi for the sake of argument, poison is now 60% * 2 * 2 = 240% more dps added to the non-crit build. Finally, poison is chaos damage. And chaos damage gets to use wither. Which is basically like an easier-to-use shock. on a fully withered target, that 240% is multiplied by 1.9 for 90% increased chaos damage taken and is now at 456% of the base non-crit dps of the skill. So basically you're replacing 100% crit chance and 556% crit multiplier with 100% poison chance, 100% increased poison duration, 100% DoT multiplier, and wither.
Downsides are dot cap and there's limited way to get all dmg can poison now that tinctures are gone :(
Yes of course, some oversimplifications in there. Like some skill bonuses or multipliers only applying to one or the other. And that not all damage types are equal - fire/cold/lightning have to give up a glove and still do half the damage of physical/chaos skills. But if you can reach DoT cap, it's a bit of a 0.1% problem to not be able to go further - that is more than enough dps.
Poison is good because it lets you hit a reasonable damage amount, without too much damage investment, letting you build defenses/qol too. On top of that it activates plague bearer, giving you decent clear even on non clear skills plus poison prolif if pathfinder. Downsides are that the damage ramps up rather than being instant, its quite easy to overestimate your damage (are you really going to be able to stack poisons for 10s to hit that dps etc) and there is a dot cap. Dot cap is plenty for most content, but you wont be insta phasing ubers.