Dragonite isn't the first pokemon you actually need to catch in fact I'm pretty sure you only get given other pokemon when you knock out or catch some other pokemon like sharpedo and even then those pokemon can be caught. Better yet why didn't you save before fighting it?
i'm specifically talking about the special pokemon like it that get given to you through events, i.e. the PTSD kirlia, the game literally blocks you from catching in battle the ones that you have to fight first, i.e. the mutant Zoroark, so i stopped trying to catch them on the realization that it doesn't work, and went into the mountain Dragonite fight with that same expectation it had established from the previous event pokemon of balls simply not working on it
also i did use buffs and statuses since most of the fights would be fucking impossible without them, especially the Steve Irwin clone that has 3 full restores, perfect held items, and in the regular game perfect stats, even most champion fights are less bullshit than that