It used to be that you could walk into your local university library, browse the stacks and read any article (provided physical access was not restricted to staff, students or faculty).
Those who could afford it may subscribe directly to print versions and receive hard copies in the mail, likely in advance of when they would appear on the shelf in the library. You could create your own library of sorts, keeping back issues in your office. You always had access to the journal in hard copy form (either through the library or through your own collection).
As the Internet became a publication distribution channel many journals began providing copies of articles in PDF form. Some have stopped providing hard copies as a cost saving measure. Some universities have stopped subscribing to the print version to save money. Members of the university community could still access PDF versions of the articles directly from the journal web site using an Internet connection within the campus grounds. Public access was provided through the terminals at the library. This could be particularly important for someone who is sick, has limited income and is trying to research and find information on their own illness.
Then everything changed.
Universities started to restrict access to their public access computers meaning members of the public could no longer access PDF versions of articles. Articles may be located in the stacks, if the journal is still producing hard copy versions and the university is paying for a subscription.
Previously back issues were always available because they were in print copy. No more with the electronic version of a journal. As soon as your status at the university changes you lose access, including to the back issues, which would have always been available in the print format days.
I wonder how many have thought to download every articles in the journals in their field in case they need access later on? Not many because they are likely not thinking about future restricted access. This content was always available before. Even more likely with the Internet.
No more access to back issues, for which they were once entitled to, for those who leave the university community and lose access as a result. Libraries may provide access to the back issues for a period of time. Those who subscribed to the journal in print format may have saved their back issues as well. But for those who were relying on Internet access, forget it.
I think this is problematic. Much of the funding used to produce the research contained in these publications comes from the public. It is the publishers that are holding back access to information by using copyright privileges. They made money publishing material that was produced by tax payer dollars and now they want to control access to it.
Now we have the open access journal movement. At least there is some hope for creating an environment in which information is available to freely to everyone with Internet access regardless of their status. However, affording to pay the publishing fee if you are a poor graduate student is another story!