Game Rant's Riley Little writes, "As one of the few non-voiced characters within The Legend of Zelda: Breath of the Wild, we asked the game's director, Hidemaro Fujibayashi, why Ganon was left voiceless."
I believe this choice was also made as a reference to how Ganon was originally a silent antagonist in the original game in 1986.
He's clearly based on Sauron and this incarnation was like Sauron in LotR's, disembodied etc.
I believe this choice was also made as a reference to how Ganon was originally a silent antagonist in the original game in 1986.