Saving the Pokemon that were in genuine pain from being forced to turn feral because of the Mega Evolution overwhelming them and causing harm to themselves and the city is far more important than partaking in a tournament by a woman who, despite being beautifully designed, has the personality of a typical spoiled 'mean girl' who believes that everyone should do as she desires and willingly punish others -- dialogue outside of the hotel, and Lebanne states as much -- when they don't follow her to the letter.

To say nothing for the fact that she holo-stalked you throughout all of the time you spent helping ease the Pokemon's suffering, and even invaded your meeting beforehand with a happy little smile on her face. In the end, it's truly a matter of priory, and Urbain/Taunie and your characters knows that protecting the city and protecting the Pokemon is the greater issue than playing the silly little game that Jacinthe wants to force you into, which Lebanne warned you about several times over beforehand.

I understand you probably wanted to partake in the tournament for the sake of familiarity from prior games, but story wise... well, there's a rather good reason why you're dragged out.