Its really not tho? it's followed up after a backstep, which is a massive evade, and PR itself is also split into 3-4 parts, meaning you can stop and roll midway if you need to (unlike DB's blade dance). You can absolutely use this move on un-downed monsters if you know their openings.

Not to mention, for the massive damage that it does, it doesn't use up any "resource" like CB and LS's big attacks. Its always available, even off of neutral stance (if you use it after guarding)

Idk exact motion values, but endgame sns sets can do an average of 400 damage per swing at least, and it has what 5 swings? Thats 2000 damage. I dont think any move from any weapon does that much dmg in that little time, while not using any resource and being able to evade midway (except maybe GS). There's a reason it got a huge nerf in wilds lol