ARR BRD was probably the closest to a support class we've had - well, maybe include AST back when the cards had specific bonuses.

ARR BRD could debuff enemy magic defense, they could restore TP or MP as well as movement speed out of battle. With changes they made to the game over the last near-decade, all that's left is movement speed. Honestly, BRD's support kit was still bad, but it was possibly the "best" FFXIV had to offer.

The holy trinity of roles simply doesn't allow for true support classes in this game - I'm talking about FFXI BRD or EQ1 BRD and Enchanter. Classes that focused mostly on buffing, debuffing and crowd control.