Compression can increase read and write speeds to storage because you’re sending over fewer bits. The tradeoff is that you need CPU resources to do the compression (and decompression).
I haven’t found games to compress that well. On my steam folder 809GB compressed down to 724GB, so I save maybe 10%. That’s certainly not nothing, but it’s not game changing either. That said I don’t install a lot of hundred gig plus games.