as everyone knows, poison is overpowered with it’s shtick buffing itself for every extra stack making volume = power with a couple of very over the top unique weapon options.
plague usually just comes along for the ride to support poison and make it even better.
Ignite is just a worse poison that doesn’t gain extra bonus damage per stack, and requires you devote most of your item slots to improving it’s chance/duration/damage to get as many stacks on as quickly as possible before you inevitably get splattered across the floor because most of your build is uniques with no defense stats.
then theres the spreading flames debuff which is just an even worse burn because (to the best of my knowledge) it doesn’t stack while it’s only merit is it spreads on its own, which is nice and all for the story when things will die to 1 or 2 stacks of a dot, but it’s not even a threat to anything in monoliths or arena.
frostbite is a cool idea, but it gets no support outside of whatever talent tree it pops up on, and even if it did it’d still only be as good as burn.
shock deals no damage over time, of course, but it’s resist shred is typically useful for the builds that can apply it in a high eough volume to matter. as long as it applies to anyone doing elemental damage to that target once multiplayer goes live, i’m sure a lightning sorc or other assorted shock builds will find their way into the meta.
bleed is only super viable in minion builds running onos tull chest piece and while that’s nice and all, minion builds have their own issues with survivaing due to the descision to put stats towards their pets to actually deal damage, or putting stats into their own defense, and thus their pets die and do no damage (TL;Dr on this one: bleeds are only useful in minon builds which have their own problems to contend with right now)
the other assorted Dots and debuffs are likewise super niche with no support outside of the tree’s they appear in (time rot is an example)
my suggestions to address this imbalance would be to leave poison as is and use it as a standard of power.
combine burn and spreading flames such that burn will always spread by default, and enemies can have as many stacks spread to them as the guy with the most stacks.
make frostbite gain damage the lower the enemies health gets (and make it scale pretty good, or give it better item support)
shock could be made to last indefinitely (if it doesn’t already, the tooltips don’t say it has a duration)
Bleeds could grant more direct power to the character that applied them (like a frenzy buff that occurs more often or is stronger against high health targets)
and so on in this vein.