Being objective, Ahri lost all of her potential assassination power in her rework. She cannot 100-0 any champion unless she is extremely ahead, yet she can still be 100-0'd by most assassin mid laners even if she's built some defenses.
She gained a lot of mobility and become really safe, but lost a lot of her playmaking abilities. Succeeding in the R-E combo on an enemy you've poked down to 70% only for them to survive anyways and proceed to 100-0 you doesn't make Ahri feel OP in the slightest.
Not to mention her Q is her lane poke so it's easy to bait that cooldown out before a gank. Her R requires level 6 (like anyone else) and has a fairly large cooldown at rank 1 of nearly 2 minutes, meaning ganking her is quite easy. As mentioned before, she's incredible squishy, so any CC during a gank will almost definitely kill her.
Her CC is quite likely the LEAST powerful true CC ability in the game. At rank 1 (which it is often left at until level 14, and definitely through 7 so for all of laning phase) it only persists for 1 second, yet it's blocked by minions, has a small radius, less than 1000 range, and only 1600 missile speed.
In contrast, take Morgana's Q: Lasts for 2 seconds (scaling upwards), alsoo blocked by minions, has a larger radius, has more than 200 more range, and is a bit slower. Similarly difficult to land yet twice as rewarding when it does.
In contrast, take Yasuo's Q: Admittedly the wiki doesn't list the speed or duration, but it feels faster than Ahri's E. The knockup lasts roughly as long, but the CC is greatly extended by his ultimate's follow up. It's considerably easier to hit since it passes through minions, although the radius feels similar.
Basically, while she has lots of personal utility in escaping, she doesn't have the damage to kill squishies and doesn't have the team-utility that other mages offer. She doesn't have the AOE damage to the same extent as champions like Viktor or Anivia or Brand do.
Ahri is a jack-of-all-trades yet a master of none. Her only real strength is personal safety, but that does her team little good.