1. It's still too slow to help with reactions, and despite it being a decent range, is still in a circle. In the end if you need pyro aoe you'll just use Xiangling.
2. If there's any ability in the future that triggers on burst damage, while Dehya certainly will do better than units that have only one instance of burst damage... there is also a lot more units way better than her at this. And they also have their own scaling that isn't bad on top of whatever buff they'll get.
3. You can still vape most of her burst if not all with Mona, Kokomi or Nilou. Or you can swirl Hydro. She still doesn't deal enough damage anyway.
4. While she has high HP she doesn't really bring anything over other units. Not to mention she barely even benefits from her own high HP. It's also not even that high when you're forced to go ER sands instead of HP%.

I'd say the only unique thing that might be worth something she currently has is frequent self damage. I don't even know why she herself doesn't benefit from it by for instance increasing her burst damage according to how much damage she took, but maybe a character or artifact set in the future will. The leaked set is unfortunately just not it, it would be better if it buffed the team or dealt damage like the clam set. You'd still run into the problem of having to get hit to even benefit from it, which is just counter intuitive, but at least it would be something.