Can Qiyana lose some damage in exchange for more reliability?

This champion is really awkward. She plays like an assassin and has assassin-level damage, but she has none of the tools needed to assassinate anything.

Her kit makes it seem like she was intended to be some sort of weird 'jungle assassin,' since she can only fully utilize her kit in the jungle and river, but her jungling is incredibly bad. In lane, walls are often too far to hit with her ult, and opponents will generally just stay in the middle, because you have no zoning tools to force them towards a wall.

The only way she can get close enough to assassinate a target alone is by using a Brush Q, which means she can't perform her burst combo, which is necessary to do enough damage to kill. You don't want to ever go in on someone unless you're guaranteed to get a kill, because she doesn't have any survivability or mobility for a solid 6 seconds after the combo.

If she's left alone in lane without any jungle intervention, she just automatically loses to every ranged champion. She's easily bullied and can't get in range to use her E against most casters, meaning she needs to use a Brush Q instead of a double Q combo if she wants any interaction with her opponent. This is often undesirable, because without the double Q, you won't kill them and you'll be stuck past the middle of the lane with no way to escape or follow up.

Since she can't win lane, the only option is to roam to other lanes. But she also does a very poor job of this. Her movement speed bonus is so low that it's basically worthless. She doesn't get any unconventional gank paths, like Kayn or Talon. She can't quickly get on top of her target from the fog of war, like Zed or Katarina. She has zero chance of a successful gank unless she's going to a lane that can lock down the opponent while she gets in range, and she also has to rely on them clearing any wards.

She basically feels like an AD version of Diana with none of the survivability and too many conditions on everything. You need an entire team working with you in order to satisfy the specific set of conditions she needs to function, but at the point you have that, you're probably better off playing something else.