Generally agree here. However the Apple icons of the pre-flat-design-era, even the really skeuomorphic ones, were always pretty great; I always thought they summed up most of their respective apps pretty well. For instance, for Gamecenter, the icon for it before iOS7 was quartered, with a chesspiece, baseball bat, rocket ship and dart board in each quadrant.
They really didn't need to change it. It's now just 4 coloured bubbles, which symbolises...what? I always thought it was just so...random. It's the most irreverent icon of the iOS home screen since iOS7.
Oh yeah, I'm not lumping icons in with controls. Their icons were fine.
Oddly, Game Center is missing from my phone, so I'll take your word that the new icon sucks. I like to scorn the Photos icon: a multicolored Spirograph. Why?
They really didn't need to change it. It's now just 4 coloured bubbles, which symbolises...what? I always thought it was just so...random. It's the most irreverent icon of the iOS home screen since iOS7.