Except he's remained relatively the same until 4.21 where he got a buff to his R so that he didn't have to save it for an execute on low health enemies.
Before that he got another buff to his R where the cast range and cast time was buffed as well in 4.8.
(ignore the +4 base armor he and every other champion got in 4.5).
BEFORE THAT he got a NERF to his E in the silence duration in 3.01
Honestly, he's remained relatively the same (minus the R buffs). It's like Lissandra; people have only just started noticing lately that "oh hey, every other ftm is nerfed so let's move onto this safe pick that was buffed awhile ago. If you're losing out to him, ask for a gank and/or build resistance to him. It's not that hard. He pushes lanes hard so a gank is easy to do