On to the next thread. For me, this one is difficult, because unlike the two prior genres, ARPGs are very much a genre that I'm still attached to.
I think ARPGs suffer from a general mindset of "if it aint broke, don't fix it," which results in a deluge of good but largely disposable games. It's a similar situation to the MOBA genre, but with more niche and indie financial success stories because these games didn't immediately establish f2p as the end-all-be-all standard for the entire genre like MOBAs did.
Do they need fixing? Not really. But something new and distinct would be appreciated. They also tend to lag behind the industry from a graphical and polish standpoint.
My idea focuses on combining existing strengths
Potentially unpopular opinion, but ARPGs don't really do a good job of making both the long term progression and the short term/low level gameplay experience satisfying. Path of Exile is an excellent example of compelling long term progression, but it's early game experience is slow and boring. Diablo 3's polished combat, fast skill unlocks, and runes make the early game immediately fun, but it's progression isn't as deep in the long term.
I think something with combat on par with or better than Diablo 3, with a steady stream of skill unlocks, a rune system for immediately tangible customization, and a deep skill web for long term customization is the best of both worlds.
To preface my next point, let me establish that Diablo-like games and Dynasty Warriors games have a lot in common. They both rely on rapid kills to create a sense of power fantasy. Both of these genres have something the other sorely needs. Dynasty Warriors needs a more compelling loot treadmill akin to a Diablo-like, while Diablo-likes could really benefit from a Warriors-esque rudimentary combo system.
In a tangible sense, if each basic attack skill in an ARPG had branching combos with light and heavy attacks (performed by left and right click by default), a lot more combat variety could be achieved. Visually, this would be represented by the skill icon flipping like a Guild Wars 2 chain skill. A light attack (left click) would continue the chain, while a heavy attack (right click) would unleash a unique animation and high damage based on when in the chain it was used, and the chain will be reset. We could take this a step further with a dedicated "ultimate" slot, which has its own resource bar and can only be used when full, similar to a Warriors Musuo attack.
Finally, I think the genre generally has a bad case of preset character syndrome. Grim Dawn offers no visually variety in your base character at all. Path of Exile has all of the drawbacks of having premade characters with none of the compelling storytelling benefits. Diablo 3 is a bit better in that it allows gender selection, but offers no further character options, and Diablo 4 looks to add visually customization, while bringing back the gender locking.
Simply put, the barbarian is not Kratos. The ranger is not Alloy. The thief is not Nathan Drake. The duelist is not Geralt of Rivia. ARPG protagonists don't have interesting stories to tell that cannot be just as easily told by another character. There is no reason from a gameplay or storytelling perspective for us to not have customization here.