The bloated file size on PC comes from developer Respawn's attempt at making the game compatible with as many machines as possible. Specifically, the game includes 35GB of uncompressed audio. Lead engineer Richard Baker told Eurogamer that "by having uncompressed audio, the game runs faster for those using slower systems." Xbox One includes an audio decoder built into the hardware, which does away with the need for uncompressed audio.
"We were a little worried about min spec and the fact that a two-core machine would dedicate a huge chunk of one core to just decompressing audio," he said.