Devs refuse to give QoL settings to toggle off battle animations because they said they want players to have to see the work they put into them. It's a bad reason to deny the feature the game should have had well before full release. As with a lot of issues it probably really just comes from them being lazy and not wanting to implement it.
Yeah, this is not the reason. Like the other comment says if we add a setting to remove the animations we would need to rebalance all the game having that time in mind and then everyone would be forced to remove the animations even if they like them to be more "optimal".