Even though he has never used this power himself, everyone knows very well—it's simply because he's not interested, not because he can't.
To some extent, regarding the matter of Embers, he could decide with a single word; all present need only nod their heads and sign, without even a chance to express dissent.
This is similarly a flaw and weakness that has persisted through generations of Heavenly Furnace, true for all craftsmen—for valuing the meaning represented by a title more than its function.
As the undisputed strongest of the Embers, if he needs to resort to the authority of the Heavenly Furnace to deal with another craftsman, it already implies that he is no longer worthy of the title.
For the power that ambitious dream of, for generations of Heavenly Furnace, it has always been a most meaningless thing, fundamentally useless.
Now, just as he returns this power to everyone, he chooses to leave the victory between Embers and Decay to the Association.
