Jett began falling out of the Meta once the OP nerf came in I think it has just taken a long time, especially in NA, for teams to realize that in the long term having a one trick Jett will come back to bite them as Riot begins to add more agents and having a wider agent pool in pro play becomes more necessary especially if we ever see picks and bans. I think 100T are getting railed just bc that's how the community is and when they see a T1 org not performing like they should especially after making a roster people tend to think that the roster move was the wrong choice. In my opinion they just haven't learned how to play the 1 duelist style yet and honestly I do think the playstyle of certain people on their team, like Hiko, who likes to play farther back on the entry and play for the clutch, have hurt them a lot especially since in the recent tournament Hiko clutched maybe once.