Akali is a higher tier equivalent of Master Yi

I am far from high tier myself, but I noticed some things between my own games that from replays I watched.

Ability to sit in the enemy team: Both of them want to be in the middle of the action, and they both do it in strikingly similar ways. -yi q makes it difficult for to hit him for players not comfortable with the game akali dashes make her difficult to hit if her player is comfortable with the game

-yi has healing from conqueror, deaths dance, and wits end Akali has healing from conqueror or fleet footwork and from gunblade

-yi has no problem getting in on the action, with his ghost on a 70 second cooldown and his q akali has no issue getting in due to her numerous mobility options

-yi can build more or less any defensive item after rageblade but still have a damage output Akali has defensive options that still contribute to her damage such as banshees, rylais, or even guardian angel due to her AD scaling

-yi can press w akali can press zhonas

-yi q allows him to be invulnerable and hit 4 targets akali shroud makes her invisible and access a different number of targets, depending on where she puts it. And for a onetrick, they know where to put it

They can chase you down from long distances

Even if they build defensively, they can still blow up any squishy carries

Both allow for consistent damage output with akali having relatively low ability cooldowns

Neither have to rely on CDR items

Them being in the teamfight demands that they are focused, dispite them being the hardest enemy to hit. They can peel for their teammates with their presence alone

Just some things I noticed. Trying to balance Akali in her current state to a wide audience is foolish, as she would destroy higher elos, just like how trying to make Master yi good in competitive would make him invincible in the majority of the player base.