I've noted that many newspapers don't provide external links as a rule, though that reluctance seems to be slipping somewhat. Unfortunately, that's accompanied by an tendency for those external links to rot with extreme speed and prejudice, which ... might actually justify the reluctance.

Linking an archived copy of the content has merits, though increasing The Usual Suspect (the Internet Archive's Wayback Machine) itself has difficulty in preserving complex content. (The rather less transparent Archive.Today is often superior in quality if not necessarily in trust or reputation, and I say that relying on it heavily myself.)

I know that I've noted news organisations which do seem to link sources relatively freely, and thought I'd commented on it previously. I'm not finding any previous mentions by me here at HN (my usual personal quips trove, amongst other benefits). Though if memory serves, the New York Times tends not to provide links where it really ought to. I believe the Los Angeles Times might have a greater tendency to. Perhaps also NPR and/or The Guardian which I tend to rely on, though I'm not certain that's been my earlier observation.

In the 19th century and through a good part of the early 20th, newspapers would not only reference specific documents or speeches but publish them in whole. In large part, this is because that was the only way to distribute and reference the material. That practice has waned tremendously, and we often see material only through commentary and reference, rather than in original form. I've come to view this quite dimly.

I'm also fairly certain that copyright is a major consideration and factor here, and another way in which it's proving a disservice to the public good.