Elizabeth:
As someone who has 25 or so music blu-rays, can second your assessment of their marginal value. In the classical field they have perished a quick death because of high production costs and low sales. The best I have are the Chailly Mahler symphonies that are memorable because of their sound engineering -- which is the best I have heard for orchestral music.
Naxos tried to offer blu-rays that could be played without a tv connection and I tried several of their offerings -- they are awful.
Have been told that Sony abandoned the SACD format after reputable articles appeared showing it had inherent noise/distortion faults in the 1-bit design.
So, this last week, bought some new Sony CD releases made after they moved to the high-res PCM format. They are incredibly accurate for orchestral textures and far superior to any of the SACDs I have gotten.
As I have stated many times, think the death of the CD was prematurely announced and that it will survive more emphatically than many streamers believe.