Re: children! terrrorists! illegal! dangerous! risk! threat! Russians! nukes! trolls! roubles!
For reasons related to health, I frequently wish to read items which are behind paywalls.
The idea that individual health is being held to ransom - and at completely unaffordable prices - is despicable.
Frequently you can find things like a single short letter published as a response to a paper from over a century ago that would cost tens of dollars to access. And at that point, we would often have absolutely no idea whether it would actually be of interest, or not.
Vast numbers of papers are downloaded and passed around as PDFs in order to make them accessible. Sometimes by their authors.
From time to time, papers are accessible prior to publication - often in draft with line numbers, etc. But as soon as they are published, they are chargeable. Hence I have many uncorrected proof versions of papers. Which will tend to propagate mistakes - from typos up - which were addressed in the final versions.
Sometimes, I have even seen official guideline papers behind paywalls.
Obviously there is a cost to providing the access, but PubMed Central (and EuropePMC) are sitting there providing fantastic access when the publisher allows.
On top of all this, if papers are not accessible, they will not be adequately archived. All too many journals have disappeared taking their entire back catalogue offline. Although copies might still exist, finding them can be close to impossible.