In Research and Academia, it is made primarily for cataloging for the future, therefore cannot allow duplicate by nature, also never throwaway.
Actually, reaching the audience is not always the primary purpose. Audience should try to reach, or even buy, or translate if possible, if it matches their review criteria (for example, Systematic Reviews.)
In general writing, it is made for PR (public relations), therefore reaching the audience is the primary concern. Duplication and being viral are their nature. It can even be throwaway, or valid only for some time period, sometimes.
Indexing and permanent resourcing are actually secondary. However, proper indexing may help reach more audience over a longer period of time.
In both, it is about the author credit, but in research and academia, it is also heavily countable as a product (i.e. having 2 always mean having 100% more than 1), therefore, the author will unduly earn more credit, and that lead to ethical concerns.
Passionate developer in Java and Scala. And sometimes, something else. A few months per year, someone calls me "professor". CoFounder of Scala By The Lagoon @scalagoon
I see. It is important to delineate the purposes.
Well... that's a through summary. Much more through that I could even think. You're thinking about it really deeply, indeed.