With a very low ban rate and pick rate. Mains and OTPs inflating her winrate to no end, Fervor + Guinsoo's buffed.
And yes, all things considered, if you are lucky enough to survive past early game and the majority of mid game, Kayle shines. Otherwise, she's just a resistance shred/ult bot with no mobility and very little utility.
Almost no one plays her, which is good, because not everyone should or can play her to the maximum of the macroplay skill she's based around of. And almost no one bans her, which is also good, because it opens up space for actually unbalanced champions to be banned.
I´m happy for the fact her VGU won´t happen for a long while, most likely for the majority of season 7 and most of season 8. And when it does, very little will actually be changed if Riot does intend to follow the new class/subclass system.