Reasoning for triumph healing being delayed?

Does anyone know if there is a reason or if a rioter has stated why the healing on the rune "Triumph" is delayed?

As an avid kindred player, this is one of the best runes on kindred as it allows me to come out on top of a fight in my ult and is very helpful as one of the squishiest junglers in the game. I can go back though my games and for every 2 or 3 games there are at LEAST 5 or 6 occasions where i die before the triumph healing saves me, which I feel should not be the case.

Triumph as a runes job is to make you come out on top of winning the 1v1 duel, but dying after I won the duel by playing better feels really bad. Unless im ignited i should not die from something the player casts while still alive, but triumph isnt enough healing to save from ignite anyways. Id love to hear the explanation/reasoning for the rune to be delayed, as least so i can feel a bit more peace of mind when i rage for "Triumph healing being too slow"