I wanted to make this post after watching the PerrythePig video on how bows are in a pretty bad place (Bow Builds? In MY Video Game? | Crit Vulnerability in Last Epoch 0.9 - YouTube)
Detonating arrow is a classic skill of marksman and used to be pretty decent, a key aspect of the skill being it would convert ALL added damage to lightning(with cold/fire options in the skilltree). This conversion combined with the suckerpunch arrow node and rapid detonation allowed you to create a decent explosion in two hits. Using the various added flat damage from bows, Elemental arrows(a node that felt tailored to this build archetype), tree nodes like swift assassin and snipers gambit, and even mourningfrost if you could fit it in would lead to a decent amount of damage with a slightly awkward required double hit mechanic(think firebrand+flame reave but you need to hit flame reave twice on the same enemy within 0.5 sec). The build was decent pre 0.9 but nowhere close to stuff like bowmage(which I switched back to) or kelthan blasting dragonsong decoy.
With 0.9 the build was absolutely dumpstered by the change removing its conversion. The explosion got a boosted damage effectiveness but lost base damage anyway, and now more than 50% of the builds damage is changed to random phys/fire/cold damage which is pretty hard to scale all together (only way is crit and marksman crit is in the dumpster right now especially for bows that don’t even get a base crit mod).
The weapon base damage rework was supposed to allow builds to specialize in a damage type but soo many nodes still say flat physical damage instead of generic damage(Sniper’s gambit, swift killer, assassin’s quiver, Once, and this is just rogue, plenty more in primalist/sentinel trees) that it feels like it was not fully thought through.
To take an example of another skill that got its conversion tag removed: Javelin, it also got a 10% reduced hit damage but to compensate, it got GENERIC flat damage from gloves, relic, belt slots and the flat throwing removed from rings was replaced with throwing attack speed still a useful mod for Javelin.
Detonating arrow seems to be regulated as just a proc/dot skill now with its main use being lightning tendrils for more hits to proc skills like icicle or ailments which is pretty sad IMO.