That’s what is making me stick to Sadhu. I see OoB as a complementary source of damage, not the main focus. It’s a good tool to use while your spells are on cooldown, and also allows your cleric to move much faster, allowing you to catch up to your party if needed.
Sadhu adds, from what I see, 2 sources of damage in the form of Astral Body Explosion and Possession, and a ton of utility with OoB, allowing you to dish out some extra damage while supporting and casting damage spells from afar.