Special:UserProfile in MobileFrontend does not seem to offer clear advantages over either an editor's own user page or their contribution history. Until there is a better / more useful implementation, it should probably just be removed.
Links to some community discussions: Lilas Talk page or the German Kurier.
Related tasks:
T85929: [EPIC] Kill SpecialUserProfile or Move MobileFrontend extension's Special:UserProfile.php and related code to a separate MediaWiki extension
T90801: Remove last edited pageimage from Special:Userprofile