User blog comment:BertH/Technical Update: March 9, 2016/@comment-25648422-20160310144734/@comment-26402117-20160310184744

Navboxes and navigation sections are currently stripped from the mobile skin on Wikia - presumably to maintain maximal mobile compatibility and ensure a perfect SEO for mobile pages. They are still the only sensible way to navigate 500+ chapters of some written series (manga or novel etc) on some wikis.