Why are review articles cited more frequently than original research articles?
I don't recall ever being told, by journal guidelines or by an editor, that I should always cite the original paper instead of a review. The review would usually contain citations of the original publications.
A review can be cited as a single source for lots of facts,  especially in the &quot;introduction&quot; or &quot;background&quot; sections of a paper. So it's likely to be more useful for the reader. A good review is also likely to be easier for many readers to understand than the original paper. And the review might be where I originally learned the information I need.  Finally, a review is likely to use uniform notation that I can adopt, whereas the original papers are more likely to have diverging notation, which may make it difficult for readers to compare them with my paper and with each other.
I've often written things like &quot;see [review] and the references there&quot;; no one has yet complained.