A relevant fragment of a post "Why do we need [foot]notes?" by historian N.A. Vlasov (translation to English - mine):
"...
So why do we need citing a source? To show, where the information comes from. Loosely speaking, to show that the information isn't made up. A note with citation can confirm this if needed. Of course, it is no "truth warrant" and it cannot be such thing.
An average reader usually ignores the notes, in the best case acknowledging their presence. But there is a lot of useful information that can be extracted from citations:
1) To look, what other papers on the topic exist. Especially useful for students. The rule "follow the citations" is one of the major principles of work with literature when writing yearly or final thesis. Can also be useful for a mere reader.
2) To critically appraise the information from the text. Sometimes, author cites openly dubious, biased or even nonexistent sources, or his own works. ... This, of course, requires some background, but most obvious problems will be clear even for an unsophisticated reader.
3) To determine real (and not stated) foundation, on which author created his work. Reviewing bibliography doesn't always give a real picture, because it can be "inflated" in a completely honest and lawful way. Sometimes, bibliography includes lots of archive collections that are very impressive by themselves. But then we start analyzing citations and find out that author cited archives only three times in the entire work and quite large chapter was written only with reference to two monographies.
Of course, dishonest authors have developed lots of tricks to deceive even a sophisticated reader. For example, so-called "borrowed citations". It means a situation when, for example, an author hasn't been to the archive himself, but takes citations to the archive collections from the monography of his more diligent colleague. But nevertheless, attention to citations can do a lot of good."
original (Russian) -
https://navlasov.livejournal.com/91153.html
This is reader's view on citations (and one of an informed and sophisticated reader, I might say), but this can be also useful for authors - to know, what this type of reader would want from their work and their citations.
PS: curious: in the comments to the post, author says that often it is the policy of the publishing house that imposes requirements on a quantity of citations. Some require more to look more scientific. Other require the bare minimum.