Garchomp EX in current Meta

I am wondering why Garchomp EX does not see much play and is not getting good results in tournaments.

I sadly do not have the card so I can't see for myself. But when I think about the deck and its matchups, I would assume it is very good into:
- Darkrai+Giratina, as his snipe can dodge druddigon, and the breakpoints also seem very nice, 1 snipe + 1 big attack clears either.
- has typing advantage into arceus, and again good breakpoints.
- probably strong into Gyarados, especially if you run hitmonlee aswell (however I could imagine Gyarados is too fast with the manaphy line)

I would guess it does terribly into the other fighting variations, any grass deck, probably all 18T decks and charizard seems difficult aswell.

But still in my head it should do very well into the 3 most played decks. Am I missing something?