User blog comment:MisterWoodhouse/Fandom is upgrading to a modern version of MediaWiki/@comment-25096207-20190620205139/@comment-20644-20190620205403

Geo-blocking on a skin level would've been pretty resource intensive, and the resource intensity (in terms of making sure the right GDPR compliance was in place for Monobook) is why it was removed in the first place. The stark reality is that not enough people were using it to justify the rising cost of maintaining it, unfortunately.

There is a script called PseudoMonobook that users put together. You're welcome to use that in your personal CSS/JS if you'd like.