It would be great to have a tool to create simple background movement. In krita documentation there's a perfect example: https://docs.krita.org/File:Introduction_to_animation_walkcycle_02.gif ideally we should create a layer with an image bigger than the canvas and give a start and end point, then krita should create all intermediate steps. in this video you can see the concept: https://www.youtube.com/watch?v=wttkDsaZMFA
This is part of what Tyyppi worked on in the summer of 2016, but he couldn't quite get it working.
Relevant task on Phabricator: https://phabricator.kde.org/T11476
Animated transforms masks are currently in Krita 5 and would be the correct tool to use for this task, Please try out the new feature and let us know how you like it!