What am I missing?

Your premise is a bit off. CD sales are up 21% and the number of units are up 47%.  Hi Rez is not much of an advantage, sound wise, than Redbook if the CD is properly mastered. In fact, it can be indistinguishable between the two types.

Personal ownership is still a thing for some as well as properly compensating the artists. Don't forget that the whole concept of streaming and sharing music started off as a way to rip off the artist and pretend you were dissing the man (record companies). I still get a laugh over that one. Now that it's SOP, let's get the tech down pat and enjoy the fruits of our crimes. The sad part is, a different group of owners are screwing over the artists and still charging you to listen without owning. Owning costs extra. 

All the best,
Nonoise

CD quality is the standard only because it was the first digital. The next was ripper files, then purchased files, now streaming.Since streaming services more and more have higher resolution files than CDs, streaming can frequently sound better (equipment dependent like all of audio). Qobuz for instance has over one half million high resolution albums. My streamer sounds better for these, in general than the CDs, and on pretty equal footing with my high end vinyl rig.

Streaming is simply an unbelievable good deal. Nothing to do with “the industry” not wanting you to own stuff. For the price of one CD per month you get access to millions of albums! This is a screaming deal. The trend has been for higher quality through streaming and the cost is going down not up. It is the future, period. I had 2,000 CDs. I gave them away. I never listened to them anymore since I got good quality streaming.

Technological trends cause change for all in the area. For the consumer, it creates real bargains. For musicians it creates problems, how to, adjust to the new world. I know some. While they are not happy with the small payments for the use of their music, my close friend makes money through concerts. They will need to work this out over time.

That is a GREAT question. I think the advantage to CD is buy once, no monthly fees, I have a choice of ripping them or playing them. SQ will be dependent on your components. To me the BIG disadvantage of streaming is movies, they are compressed and sound weak compared to a 4K UHD BR in Atmos.

I have owned hundreds of movies in laser disk, VHS, DVD, DVD special addition, Blue Ray and on line. So, conservatively I have spent $500 on copies of permanent copies of Star Wars and many other movies.

I bought vinyl, audiophile pressing, CD, and HD copies of Kind of Blue.

We can stop this madness now. Over the next years the best available will become what is on line as all content becomes so. All documents, music, video, photographs…

People will always want to own physical media. Vinal, CD or DVD. Not seeing any of those formats go away in most people lifetimes. 

In 80's and 90's they said vinyl is dead. Guess sales just slowed and with most things it is all part of the cycle.

I am enjoying the heck out of the cheap prices on CD's