I love Riot's Balancing. I really do.
Somehow after a split of being a High Pick/Ban priority, Riot finally nerf them... so hard they completely drop out of competitive play.
(E.g. Gragas BOTH TIMES. He was a strong mid so Riot Olaf'd him until he got a rework, then gutted his wave clear so that he gets shoved into turret 24/7 when he was meant to be a lane bully top.)