Users want to know who wrote started the article they're currently viewing. The action=info page provided by MediaWiki uses the initial revision to attribute as the page creator, but this is not necessarily an "author" of the page, per se. Say the page began as a redirect then someone changed it into an article; action=info still points to the author of the original revision.
The page creation log and the revision history do not clearly indicate who actually started the article, and it is not cheap and/or accurate for tools to automate this (even going off of tags).
The most common need for this is with tools that list pages that a user started, for instance https://xtools.wmflabs.org/pages. A common complaint is that pages show up that weren't actually authored by the user (they created a redirect, and later someone else turned it into an article). In order to fix this, we need a quick historical reference to when this change was made and by whom.
Log redirect changes. That is, the change to a redirect, or the change from it, noting the relevant revision ID and the performer.
I do not think action=info needs to pull in the last article-from-redirect change, but having a proper log in MediaWiki would at least allow for easy reference to redirect changes, and allow other tools to deduce who the original author is.
These tasks have stalled due to the lack of a redirect logging system: