No one has mentioned Garuda Extreme yet? Provoke is the only method of taking the Spiny Plume off of a target.

Provoke is also the only likely way to pull apart the second sister from Garuda (if the main tank takes the first + Garuda).

Provoke is very likely needed to catch up to the main tank in T5 (after the adds in phase 1, or at any point if the main tank dies), unless they are managing their combos to stay just above the healers (if that's the case it's a serious DPS loss).

Basically in any situation where there's two tanks (e.g. all of Coil and Extreme Primals and Crystal Tower), Provoke makes acquiring and swapping enmity much easier than having the other tank play a careful dance of enmity to make sure they are less than one combo above you. Even with Provoke, you usually want a charged up Skull Sunder or Butcher's Block to cast immediately to prevent the previous tank from re-taking enmity. This is especially so if, at any point, you are not targeting the same enemy as the main tank.