To a degree you are correct.... however there are major differences between video and audio.... and, in the end, I expect them to make a significant difference there.
What you have described about "what we all expected cable to become" is actually largely what it has become.
My cable service does offer one channel for old westerns, and another for old evening sitcoms, and yet another for very old horror movies.
I could have over a thousand channels if I signed up for the big package... and they have a LOT of movies on demand as well.
Some of the main reasons so many shows still remain unavailable is a combination of lack of interest, licensing costs, and simple space.
The other is that we currently lack an in-place way to effectively "commercialize and monetize" those old movies for which there is little interest.
Someone has that old cartoon you want to watch... and they would cheerfully sell it to you for $1... but they have no way to actually do so.
Even though DVDs have become cheap, there is still effectively nobody who has come around to offering video DOWNLOADS, and no standard for doing so... yet.
I recently purchased a rather obscure (recent) album from Amazon.
I purchased it as a commercial CD but, when it arrived, what I got was a CD-R with an obviously ink-jet printed lable.
It looked like a bootleg copy, but an enclosd slip reassured me that it was legitimate.
"Since there is so little demand for that album it has not been issued as a commercial CD disc. Instead, Amazon has been licensed to print copies directly, when they are purchased."
We have also in fact had a recent attempt to do something similar for DVDs.
Some time ago Walmart offered an option that, if you owned any DVD disc, you could turn in the plastic, and they would....
"Exchange it for a digital copy that you could play on any of your electronic devices via your favorite streaming service".
What this meant was that they would accept your physical disc, destroy it, and trade it for a license to stream the movie.
(I don't know if this still exists or not - or if it was a commercial flop.)
My point is that, if the trend away from PHYSICAL digital media continues, this is the obvious direction in which things will eventually go.
However, the physical CD-R disc that Amazon sent me will disappear from the process.
Someday, instead of buying a used CD for $2, what you'll receive is either a copy of it as a digital audio file you can download, or a license to listen to it on your favorite streaming service.
And, if you sell that old CD, instead of being piled somewhere on a shelf, each disc will be carefully shredded, and "the licence it embodies" will be added to a server somewhere.
The technology to do this has been around for years...
The ONLY current sticking point is licensing.
Our current laws have simply failed miserably to keep up with the technology.
The music industry has traditionally had a seriously flawed idea about ownership.
The "official part of the music industry" will tell you that, if you purchase a music CD for $15, the plastic disc costs about $1, and the remaining $14 is being paid for the license.
Yet, by that logic, if you were to accidentally damage that disc, you should be able to purchase a new piece of plastic for $1, and transfer your license to it.
Likewise, if you long ago purchased a vinyl disc with that music on it, you should be able to purchase a CD style disc, and transfer your license to it.
Yet, instead, they now claim that the license is NOT separate from the plastic, and cannot be moved to a new piece of plastic.
(Now, magically, with the loss of that $1 piece of plastic, the license you paid $14 for has mysteriously vanished.)
And this outdated concept - that the license and the actual physical plastic are one and the same - is what is locking us into the current situation.
If I have an old album I don't want, and you DO want it, I can sell you the plastic vinyl album or CD, in exchange for some money.
The law allows me to do so... and this has been accepted reality for so long that nobody questions it.
Yet there is no OTHER WAY in which I can simply transfer ownership of that album to you in return for money WITHOUT THE PIECE OF PLASTIC.
(In essence, at this point, the CD itself is merely "the token which holds the license".)
What's missing is an alternate LEGALLY SANCTIONED MECHANISM whereby I can transfer ownership of the license.
However, because the current combination of music streaming and music piracy is well along the path towards destroying this outdated system...
We can reasonably expect that it will eventually be replaced by a newer and more practical one.
For example, instead of selling my old CDs to "ye olde CD shoppe" I'll be able to go into a shop and sell them my old pieces of plastic and their attached licenses.
They will then immediately RIP and shred the plastic discs.
They will then have digital copies of the music itself...
And the "licenses", each of which entitles one person to own and play the music from one of those discs, which they have 'recovered" or "extracted" from the discs themselves...
You will then be able to purchase a copy of that file, and the license that entitles you to play it, from your local shop.
Once this happens, every CD ever made will eventually end up in a worldwide database somewhere, where it can be easily downloaded by anybody.
And, once this occurs, you can bet that SOMEBODY will work out the details of a new licensing protocol to go with it.
(It would be foolish to delete the file after one download. There must be SOME way to sell more copies, collect the licensing fee for them, and distribute it "fairly".)
Of course, the music industry would prefer to prevent this, so there is no way for the owner to "recover his license form the plastic and has to buy a new one".
However, the obvious ancillary point to all this is that the practical aspects of the market and the technology will force this to happen, and sooner rather than later.
In the real world....
If you, or somebody you know, has "the last copy of that rare CD available on the planet".....
They're going to rip that disc and make copies for their friends.....
And, while many people might feel a touch of guilt about "stealing an album they should have bought".....
Very few people feel any guilt whatsoever about "acquiring a bootleg copy of an album that is otherwise unavailable"....
Therefore, in a sense, the music industry is essentially "racing against the clock" to find a legal way to sell that music before it becomes available for free....
(They basically need to find a way for you to sell that copy, and get their "fair share", before you get tired of waiting and simply start giving it away.)
And, yes, if you have or want some album that's really obscure, it may never "find its way into the system".....
However, as such a system becomes more ubiquitous, and more readily accessible, that barrier will be lowered.....
I can literally envision a day when EVERYONE has a streaming account somewhere...
And we are each offered a $1 credit for every CD we send in that they don't already have in their database.
(And every song, on every disc that's sent in, shows up on everybody's streaming service the next day....)
This will happen the day the music industry is forced to remove their collective thumb from their collective ass....
And that day is coming soon.... as the current business models for selling discs continue to become progressively less able to support the industry.
(We may, quite literally, see a day when physical discs simply become unsalable, and the streaming services become the ONLY customers who actually purchase music.)
We are already approaching this point with video....
Netflix, with their production of exlcusive content, has now become one of the top few remaining major studios....
And many stores have alreadys topped selling DVDs and Blu-Ray discs, or are discussing doing so....
And, if you try to actually purchase CDs, you will find that the list of places that carry them are dwindling rapidly.
(My local "vintage music shop" also no longer buys or accepts them for trade-in.)
Considering how rapidly streaming has risen from a novelty to dominate the market....
It seems clear that this is what the majority of customers actually want....
I remember when cable TV started. They said there were going to be over 100 channels, and each one would be different. One would show crime movies from the 30s, another would have 70s TV sitcoms, another would have classic cartoons... with over 100 channels, that should cover everything, right? Well it turned out that there's over 100 channels of basically the same thing. There are three or four channels that air legacy titles. Even the classic cartoon channel started airing modern live action shows. Streaming won't reach down that far ever. At some point the CDs that contain the music that streaming doesn't cover will be as rare and sought after as the LPs that Japanese collectors snap up, and the pre-war blues 78s that go for hundreds of dollars. If your tastes extend beyond the average consumer, you will either have to buy obsolete media or do without. If you're a normal consumer, the market will give you all you want.
In the meantime, I have a huge collection that I am digitizing and will have the best of both worlds. It isn't about format. It's about availability of the music.