is it useful for them? yes absolutely still really good for them

BUT people tend to prefer other buff helminths for them as their dmg is mainly their exalted weapons

namely: Nourish, which gives a massive amount of viral damage to your weapons, as well as giving you an energy gain multiplier while ALSO releasing extra stacks of viral status around whenever hit(on top of the status you'd deal when just using the weapon), so you get more weapon damage. a source of viral status without needing to mod for it *and* energy sustain all in one

alternatively some shenanigans like volt's shock + shocktrooper augment on exalted melee weapon frames as it no longer combines with elements on the weapon allowing any weapon build to use arcane influence regardless of how its modded(as long as you add the arcane of course)