The battleaxe suffers no damage falloff as you hit several enemies with the same swing. In this, it shines over the Atgeir's alt-fire because that attack deals less damage + costs more stamina.

Is it slow and cumbersome? Sure. Does it not help that it has no blackmetal or Mistlands equivalent? Also yes. But as with the other weapons, there's practice involved in deploying it when and where it's most useful. The only issue is, that "shining" moment is also when you'd use the Atgeir's alt-fire for its superior stagger potential. And that the Atgeir is faster and has better reach, stamina cost be damned.

But if you don't need CC and you just want a cost-efficient way to damage 4+ enemies, absolutely try swinging the Battleaxe in mid-air. It'll do wonders.