"Use key to progress the dungeon?"

[Amenian]

I think there's about two dungeons in the game where you might actually not want to - Tam-tara normal and I believe Haukke normal both have doors that, once unlocked, will generally cause the mobs right behind it to immediately come after you.

That said yes it's so frequently redundant.

And in both cases using the key is pointless in the first place. In Tam Tara, when you click on the thing to give you the rosary, just have it dissipate the wall instead. In Haukke, why do you even need that door in the first place?