With few exceptions, video games have been keeping their assets on disk in compressed form for a long time. It's a major embarrassment when someone ships a game with uncompressed audio, and impractical to ship with uncompressed image, texture or video assets (though these can be shipped in compressed form with unnecessarily high resolution).

The hardware decompression acceleration in new consoles doesn't exactly make it easier to use compression for the game assets. Rather, it makes it practical to load compressed assets on-demand instead of reading and decompressing into RAM during the loading screen.