I think Riot doesn't really understand the real issue! Ahri's dmg is not a problem! Killing enemy adc just with w-r and item actives isn't a problem at all. Plenty of mages can do exactly the same, LeBlanc, Syndra, Fizz, Annie, Ekko, Orianna, Veigar, Viktor, Kassadin...and many more!
Ahri's dmg and wave clear isn't an issue at all! I would argue that it is even on a weaker side.
The reason why Ahri has high win % is her mobility! She is very safe pick and players die much less with her then with any other champion! That alone carries games. Most of players do not now how to position, most of them overextend, and all of them get punished. But not Ahri players!
If you do not die, that means you got extra gold. If you waste their time, that means you got extra exp. That is why she is strong. She buffs her team by not dying and escaping ganks, even more if they used their summoners trying to catch Ahri, and even overextending themselves and get killed by Ahri's team in the process. Those who really want to catch Ahri can waste a lot of time for it, thus getting less experience, less gold, and less map control!
Ahri's OPness comes from her mobility, not her damage. She needs buff in damage, and nerf in mobility. I would argue even a small rework, changing Q move speed, or something with Ult (she doesn't need to have 3 charges, 2 is enough, then balance her from there)!
Btw, I think her W is completely shit ability, useless in lane, useless to last hit, and too strong for just button press against her target (it is too simple and braindead ability), and I would like to see a complete rework of it