User blog comment:MisterWoodhouse/Social Activity, the 2010 Editor, and Unpausing Migrations/@comment-45030543-20200923003403/@comment-30551213-20200923053625

Just as a bit of context, the current platform is based off 1.19 MediaWiki 1.19, which was released in 2012. The current version, 1.34, was released only in December 2019, and the next version will be released very soon.

The Wikia team have complained about having to hack fixes that come as granted in newer versions into 1.19, and I guess they had enough of maintaining software that even the original MediaWiki team have long left behind.