Let's use an analogy. Let's imagine that every single champion, every single character in this game, can be summed up in the form of a singular weapon. Let's say Akali is a dagger (apropos considering the nature of the champion). Let's say the dagger is too effective of a weapon, to the point that it is crowding out other styles of knife weapon. What is the solution here?
What does the dagger excel at? Stabbing. It is designed to be used as a pinpoint accuracy impaling weapon that hurts when used on any part of the body, but is especially effective and deadly when used on the exact spot that will kill a person if stabbed there. What else does the weapon excel at? Well, it can be thrown from range as well, which requires a bit more skill than just stabbing, but this makes the weapon multifaceted. That's pretty much it. Yes, you can slice with it too, but that would really only be effective if you're using the very tip of the weapon because it was only designed with stabbing in mind, so the sides are duller, more for blocking or riposting than inflicting harm.
Now lets say you want to nerf the dagger. The core facet of this weapon is the tip. This is what makes the weapon the weapon. Without it, it loses a huge part of its core identity. Let's imagine that to solve a power imbalance, you decided to snap the tip of the knife completely off. What happens? Well, the dagger will no longer be able to impale effectively, and the aerodynamics of the weapon are now thrown entirely off because the air resistance coefficient has been severely increased by the now flatter tip of the dagger. What do you have left? Well, I suppose now you can hurt somebody with the jagged edges where the point was snapped off, but that is far from what the intended use of the weapon was, and it is now a significant failure of design because it can no longer do what it was designed to do well.
Compare that to more subtle approaches, like making the knife heavier on one side, but only very slightly. This would unbalance it and make throwing it a much more challenging prospect when it comes to accuracy. The thing is though, you can adapt to this difference by altering your technique. So, the dagger has not lost what makes it special, but is now more challenging to use. The same thing goes for Akali.
