What is really the purpose of streaming??

I'm not sure what the OP means by "purpose" of streaming, but one obvious advantage of streaming is that it gives younger music fans immediate access to vast amounts of music that would have otherwise taken them large amounts of money and years of time to accumulate.  Back in the 60s I would have loved to have had a multi thousand album collection of rock and pop records for $10.  WOW! 

If i like something i would rather just buy it on cd. And they are mine to keep.Not renting songs.

The beauty is there are more choices for everyone. But it's a subscription service - a model which is being adopted by many internet/software services. Back in the day I never thought of it as "renting" a newspaper because there was a new one coming tomorrow. Except this is better because you can keep your songs tracked at your finger tips.

I have physical media and now its all stored. I went throught the ripping, acquiring, curating and storage media anxiety stage. Now I figure I'm free of that part and have more time to enjoy the music. More choices for everyone, it's awesome!

The OP states he likes classic rock which can be found on all the major streaming services. But I listen to mainly Classical, a genre which these services are lacking. So, what's a boy to do?

I'd like to get away from the ripping and downloading process to my Mac, with the USB cable running across the floor to my DAC for playback. 
Primephonic looks good for streaming classical, but to also listen to rock I would need to subscribe to two services.

Does anybody have a solution to my dilemma? I have a large CD collection and ripped files, but so far it doesn't seem like streaming offers what I'm looking for.

Although I've been listening to my ripped CDs for many years, I now love listening to Tidal as well.  Now I don't have to buy new CDs if I don't want to (with the one problem that building a Tidal library is nowhere near as convenient in terms of organizing the library as you can get with other apps for a ripped library.  This is why I'll probably move from my current squeeze-box based server to try Roon).

A MAJOR benefit I've found is that I can sample so many different artists work on Tidal. One of the best ways of doing so is in my current iPeng music streaming app, which has setting like Apple's "genius" which monitors what I'm listning to and suggests other songs I may like.  Tidal is integrated, so if I've just listened to one song in my own CD library, often there will be songs listed available from Tidal right after it, of similar music or artists.  And most often I really like what I hear.  Often enough I'll start off with the intention of listening to my own ripped CDs, but end up drifting away for the night through the Tidal suggestions and really discovering some amazing music. Then I save the ones I like to my favorites.

I simply cannot get enough!!!! I’m streaming via tidal and room and I’m on a musical oddessey every single day- Quite honestly, I can’t wait to get to my office to fire up the hifi- As a kid in the 80s I had tons of albums and cds, and I still do- and high end gear to play them on.  I just have no time or desire to go that route any longer when a daily audio acid trip is available on line streaming cd quality stuff. I can span Pantera to YO YO Ma in the same day- I’m listening to stuff I would never have found otherwise. I’m not much of a religious guy but when I first got into Pandora it was like a gift from god because real cool tunes and genres I had never heard would just flow into my world- unfortunately Pandora sound quality doesn’t cut it in my office system but none the less, streaming is just where it’s at for me- Between my hifi set up and Netflix/you tube etc, I’m ready to blow up my cable box and just stew my life in cool rock and roll stuff- 
Stream on my wayward son.......