The one thing I disliked while watching the Digimon Adventure Tri movies is that Meiko (who was the new character for the films) took WAY more focus than the original 8 Digidestined/chosen children
This could be my issue, but I dislike it when a character archetype is known for being shy. I am shy, but having that as a character's only defining trait makes the character dull to watch. Also, while watching the movies, Meiko felt like someone's fanfic oc at times when all the characters they interact with adore and love her very much, and she and her Digimon partner are extraordinary throughout the plot's run.
I feel like she was only made as a character just so the writers could give Taichi a love interest and further establish that the 02 epilogue is still, in fact, canon. Even then, the two of them lacked any chemistry.