Its just that you become predictable. The other teams can have easier reads on your playstyle watching your gameplays in the previous events. Same happened with the teams after Reykjavik. Only 3 teams from Reykjavik made it to Berlin. Its how the game and meta works.
it's because team strength changes quite quickly, yet we only have tournaments every few months. If we had a tournament every two weeks I think you'd see a more gradual rise and fall of teams