evidently a lot of games dont compress their audio files at all, so a ton of data is wasted on that by itself. theres really no excuse for that because there are plenty of lossless compression algorithms and compressed files will often have faster loading times because the disk read speed is the limiting factor even with the added computational cost of the decompression. thats also true for all the other game files such as textures and meshes and whatnot, which are often also uncompressed.