Earlier quoted context omitted.
If you compress data, it will be smaller and require less i/o to load, so it will load faster. That's ESPECIALLY true on HDDs, but even on SSDs there are decompression algos that run faster than SSD bandwidth. The uncompressed asset cargo cult is hurting everyone who plays their games, no matter what kind of disk they use.
if it's on a modern SSD you can DMA it directly into the GPU no CPU required
GPU decompression is also a thing though, so compression is still a way to save I/O.