Ahri does trade her Dmg for Safety, if you make her blow her ult to get away she losses a good chunk of her DMG. Inless she's fed you need to Spirit Rush, Charm, Orb, Fox Fire, Spirit Rush to kill someone, you may even need Ignite or the third proc. That's with Thunderlords and every other %dmg enhancer.
Alot of Ahri's dmg is tied into her two skill shots, those can be dodged fairly easy by predicting and not running in a straight line. Ya she can re position with her Spirit Rush but once that's down she's fairly weak/sitting duck.
It takes Mao awhile to kill someone even with RoA. He's not Hec or Vi