I find that to be highly misconstrued. Netflix is merely a lot better and easier to use modern equivalent to what rental stores did. It's audience is always there but never enough to take over, because the main population will always want to own it. When you say the trends, those trends will lead to digital overpowering and possibly replacing physical. This does not lead to a future where streaming is the majority for many reasons.
One of the first one is access. A Netflix institution only has what it has for a limited time due to contracts. There is never a guarantee something will remain there. Hence force the mentality buy it, and you have a copy to watch whatever you want is still engrained in people's heads. This is why you never had the public library killing book stores and video rentals killing video stores. It's all healthy to accommodate that audience. Now as i said Netflix is by far a lot more easy to get what you want when you want than a library but it still has limits, unless someone has had a sugar-coated upbringing only in that world. A fake-scare such as Streamageddon only highlighted this to people.
Now this being true, there is no reason to lazily jump to digital = streaming relations. Digital storage and cloud technology are coming up in the world. People are adapting it and one day i have little doubt most of our entertainment will be delivered this way. Personally within my life time i doubt it will fully happen but i feel safe in knowing when i'm an old man the other industries will have undergone the same transformation as the music industry. But what will not change is that people don't have faith in everything being held by a service that may not have it all the time. Digital downloads for films seems to have a lot of strings attached today as it's still kind of a wild west. Your own story post here showed us not that many people are moving towards that yet, but some are. As it becomes more accepted i'll bet anything it will be more streamlined with expectations.
But the biggest thing to point out here is the MONEY. We live in a world where we expect money making and earning wealth. No streaming company will ever have the money to own everything to give people access too. As long as this is true the other companies will always limit their capacity and if they start their own streaming alternatives will never put their whole library there all the time. Especially when no matter how you cut it, they will always be able to make more money from DVDS, Bluray and Digital Downloads then they ever will getting someone to pay a streaming fee.
Now all this being said both types will always be available to the public. One will never really eliminate the other. The form of each can change. Afterall as i predicted digital downloads will probably replace DVDs and Blurays. The current devices for streaming services may be replaced by something that makes it all the easier for there customers to get them. The future is about changing, but this is not the case of one replacing the other. To use an analogy the cheese burger never put the hamburger in the obsolete pile. Both exist because plenty of people don't like cheese. In this case the streaming/library will always exist for those that want to view something once or try something out before buying. It won't ever replace the people buying a copy, but it will always have it's fair place in the industry.