Yamato managed to protect Momo like Luffy asked and is holding Kaido off from hurting anyone else beyond Kinemon. Somehow, I don't think those would amount to being small matters.
It's totally possible to reach the same objective with one less character.
Right now, Yamato is a character that has been living off its hype for over 30 chapters. I'm already tired of him, and I feel other characters would have shined way better if not for him hogging the spotlight so much over the past three volumes or so.
Right now, I'm just tired of this arc. It's been an endless lukewarm romp in which the stakes never rise enough, yet the resolution never comes either. It really feels like it's stalling, and Yamato is part of the problem, as the character hasn't gotten any meaningful exploration in all that time.