Kindred mains average a 62.4% win rate with them, the highest of any champion.
And people just picking them up average a 47.27% win rate on their first 5 games, and are above 50% beyond that. To put this in perspective, Azir starts at 44.06% and ends up at 55.06%, and Yasuo from 43.88% to 52.42%. (Source, for platinum and up ranked games this patch)
She's also the third most picked and second most banned jungler, and over a 90% pick/ban ratio in MSI, where she's won 15 out of 26 games. This isn't some obscure champion festering in the shadows of its mains, like Shaco or Fiddlesticks, this is a champion picked or banned in the majority of games.
And her core item, bloodrazor, is getting seriously buffed next patch.