Just need to say...

Skills like Benediction don't suffer from "input delay". They are specifically designed not to generate an effect until the end of their animations. Look at Demolish or Venomous Bite. They apply the effect after the strikes have struck or the arrow has sunk in, not on the first blow or while the arrow is still in flight. The same is true of most defensive effects, which will activate at some portion through the animation, no sooner than half way and most not until its completion.

(Benediction then further suffers from both your own ping and the receiving player's ping, both. This part there is no fix for apart from more server locations to be nearer a greater percentage of the various players and their computers. Admittedly, XIV performs poorly on that front.)