User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-25999669-20201127142046/@comment-1038387-20201128130300

The 2006 editor, upon which the old source editor was based, was retired by the MediaWiki Foundation. It can no longer be used. But yeah, as someone who uses a lot of tabs for quick edits, even the 2010 source editor slows it down considerably.

Category Exhibition was a custom feature that seemed like a good idea at the time, but has since become a burden in terms of SEO. Every tab on the category is treated as a duplicate of the first, and search engines (okay, Google) punish sites for duplicate content, which is considers page stuffing. Mediawiki's Categories in general predate any thought of SEO, but the classic categories at least have 200 on a page, not 16.

Special:NewFiles isn't new; it's the standard MediaWiki feature. However, the missing captions, also (not) seen in categories, seem to be a result of Fandom's tinkering elsewhere. It's probably already ticketed for a fix.