As far as I know he got some nerfs and than buffs and nerfs again so he kinda fell out of favor. I may be wrong but look at Elise for example. I barely se her in my games, when I played Rankeds (Plat III) I thought I am the only one who plays her, same goes for normals, saw Elise few days ago once and she sucked. It looks like Pros pick her only because of her 1st 15 minutes and team comps, other than that She can't even duel an ADC anymore. I remember back in season 3 when I was able to literally 1shoot a squishy as semi tank Elise xD
Kalista and Kindred are literally deleted, Sejuani got nerfed because of cinderhulk while they also nerfed that Item leaving Sejuani in a dark corner. At the end, do I have to mention Rek'Sai who got only nerfs and nerfs to the point where she doesn't have damage nor utility anymore, she's literally just a flash+knockup bot.
I have never bitched about nerfs because I have my mains and I will always play them no metter what, since I don't care about current ranked system and climbing untill Riot removes Dynamic but I am really sad about current state of a jungle. Junglers are forced to play 3 champions at max in any kind of higher Elo (rank/normal) if they want to stay relevant.