Been playing as and against a lot of Senna lately. I'm noticing that she's basically pick or ban at this point. She's currently sitting at near a 52% ban rate in Silver+, which is already frustrating because that means that people who want to play her rarely get the chance to.
She also has nearly a 25% pick rate. A quarter of all games in Silver+ have Senna. Also frustrating because she tends to be picked first every time, meaning that you have to be extremely lucky to even get to play her, if you even make it through champ select without a dodge.
She also has a 52(ish)% winrate, which is close to "balanced" I suppose, but from what I understand 52% is a relatively high winrate.
And her ban rate only gets higher as you climb the ladder. In Plat+ she has a 62% ban rate.
TL:DR Senna needs a couple of small nerfs to lower her viability to keep her from being such a pick/ban champion.
Also, it just doesn't feel good to play against imho...
[References for Stats](https://www.leagueofgraphs.com/champions/stats/senna/silver)