Clemency is still useful on prog since it can save a try if something goes wrong.
Sometimes healers die, and clemency can do 40k-90k+ heals each, helping the party to survive and keep the try and not wasting time just because the healers may feel offended by a PLD's heal.

They already nerfed PLD's cover and it's utility. It wouldn't be wise to keep nerfing utilities here and there; jobs would be really boring if we keep nerfing them.