"Half the champions in the game have been played at worlds, diversity!"

Yeah, but one game on a champion isn't as equal to the same 4 being picked or banned literally >95% of the time. A champion being played once doesn't even somewhat compare to that. And hell, there would probably be even less champions played if Gragas and a couple others didn't get disabled, but because Gragas was disabled literally a third of the jungle picks was taken away. So if Rek'Sai or Elise was banned, a champ that hadn't been picked yet HAD to happen.