Are you sure about that? Hardware acceleration seems to be working on both SailfishOS and Ubuntu Touch. From what I gather, the main issue is the Wayland protocol interfaces not being up to date (SailfishOS, but also sometimes with Ubuntu Touch), not proposing the standard interfaces (SailfishOS), or not quite yet featuring all the stuff they need for hardware acceleration but this lack is being worked on (Ubuntu Touch). Applications ported to these systems are modified to match such restrictions (use Mir on UT until Wayland support is fully there; use the peculiar Wayland interfaces on SFOS)