I think that a lack of conflict between the playable factions isn’t really what’s hurting Horde lore the most. If anything, the utterly butchered state they’ve left the entire setting since the end of Legion can be seen throughout every avenue the writers have touched ever since.
It just so happens that the Horde has been a topic they’ve touched up on quite a bit, then discarded like an used tissue and without warning in 8.2.5, leaving us in a cliffhanger on what the state of several major factions of the Horde are, with some lasting for over two years, and some others lasting to this very day (as of time of writing).