I can testify that the CD layer of SACD hybrid is BETTER than the same music same recording from a previously released CD. Yes I own both of two performances now.
Classical, and the hybrid disc CD layer sounds better than the same performance on an earlier release on CD. (Being played by one of my five disc CD changers to the Marantz SA-10 as a DAC.)
I would think it is due to more care in the transfer from the master tape?
As far as compression, I only own Classical SACD, and I have to say they sure are not suffering from compression. For Rock I have no experience. I have not bought a new Rock CD in over a dozen years. About eight years ago I bought 2,000 used Rock CDs... Then resold about half.
I bought used Jazz CDs, Classical used CDs SACDs...