Riot is emphasizing too much on counterplay in champion design these days
"omg Nami W and E is a point-and-click soo fking unbalanced $@!% gut this champ to oblivion" -said no one ever. "fking jhin Q and 4th aa how am i even supposed to dodge that point-and-click?? 0 counterplay no skill champ rito fix this sh**" -said no one ever. "the most overpowered thing about ahri is her W and R because unlike her Q and E, it is auto-targetted ability and u cant even dodge it no matter how good u r" -said no one ever
They are not negated completely even if misused unless yasuo pops up windwall. They are guarenteed a minimal amount of contribution even when used in un-optimal situations. On the other side, the minimal contribution takes up enough of power budget that optimal use isnt game-breaking either.
It's not coincidence that win rate for nami, jhin and ahri do not fluctuate heavily from one elo to another elo, fluctuating only within 2% excluding master and challenger where a single 1-trick player can make data unreliable. Just having partial counter play can be good enough.
It's not a coincidence that your RitoData™ indicated that ahri didnt need nerf for months.
It's not completely a coincidence that nami did not need any buffs or nerfs since patch 4.13 aside from LC$ buffs, bug fixes, and champion roaster-wide stat changes, and still does not need any real buffs/nerfs to this date. They are still considered healthy in general.
Just my thoughts after seeing Riot's trend on emphasis on counterplay these days.
EDIT: geez what's up with all the people that dont even read the post and comment nonsense s**t
to be very extreme. So it is a concern regarding riot's trend so far. It's either break the champion to balance it or make it useless to not break the game if trend continues too far. And it's already a problem depending on what you believe is the acceptable difference between fail/success cases.

W&E,
Q,
W&R are not completely stat-checkers. There still exists a fail/success condition where fail condition still does something even if it's not optimal, and success condition is allowed to be gated by the fail condition, which keeps their win rates consistent across all elos to within 2% difference.
To add on to it,
is also a champ that i'd say is healthy according to what im saying. 2 of his skills are point-and-clicks that are guarenteed to do some minimal contribution no matter how retarded the player is, and yet they provide some sort of partial counterplay as well to prevent him from doing too much as well. His win rate difference between bronze and diamond is also within 2% difference.