There are items that can help with "long cc" problems.
and if you're on TT
is a open option. Also mentioning Charm's duration are 1/1.25/1.5/1.75/2 Then compare it with other mid laner's cc duration. Also take a note that Charm is usually the last one that is maxed out in most cases.
Ahri - 1/1.25/1.5/1.75/2
Veigar - 1.5/1.75/2/2.25/2.5
Annie - 1.25/1.5/1.75
Lux - 2 at all levels
Leblanc - 1.5 at all levels
Vel'koz - .75 at all levels, noting this is a knock up.
Viktor - 1.5 seconds at all levels
Xerath - .5 - 2 seconds depending on range traveled.
Brand - 1.5 at all levels
Nerf the range of Spirit Rush? Its only a slightly longer than flash range, and making it shorter kinda ruins the idea it being an ultimate ability. There are plenty of champs that can keep up with Ahri. Let alone any movement restriction items hurt like slows, snares, stun, etc.
The only time when Ahri can really jump on you if you're squishy and behind. Let alone her style of being classes as a burst mage by Riot, yes she's got a pretty low burst damage compared to other burst mages, also having low scalings in comparison too.