1. It changed a lot. the companions all had different dynamics with each other.
Different dynamics with each other? Sophocles interactions with the rest of the characters were hardly unique or special. Mallow only had good interactions with Lana and sometimes early SM Lillie. Kiawe had good interactions with Ash and Lana and that is about it.
2. Much as I love Bonnie, she didn't do much until XYZ.
And Mallow didn't do much throughout the entire series. Lillie did next to nothing other than learning a Z-move after the AF arc, which was nearly 87 episodes. Sophocles was mainly there just to be irritating and occasionaly have an episode with his Vikavolt like once or twice.
3. Mythical is a subset of Legendary. All Mythicals are Legendaries, but not all Legendaries are Mythicals.
Mythical Pokémon are an entirely different group altogether and they have always been presented as such in the Japanese media.
4. All of them made it past the first round, the two weakest ones got eliminated in the top 16, the next two lost in the top 8, and one made the semi-finals.
Idk about you, but getting past the preliminary round is hardly an achievement when the battle format is an unfair game where you can gang up on people with your friends to win. Lana had the luck to go against an even less developed trainer than her, while Sophocles won because they managed to completely screw over Acerola's character.
Kiawe was basically the only one who had any real presence there between the classmates.
5. This League couldn't be traditional. There was no time to fairly set up entrance requirements like passing the Island Challenge or something similar because the League began far too soon after the announcement. And even so, the two people who ended up as finalists are ones who completed the Island Challenge.
Yeah a few of them out of almost the entire Top 16 completed the Trials. Many of them didn't have a full team nor had that much experience battling. Some even had only 1 pokémon. They totally didn't earn their place there. And that is supposed to be a good thing how...?
This League is a positive. We got to see every battle, and only one or two of them were mediocre. It felt like a real tournament, unlike recent past Leagues.
Only one or two were mediocre? Pretty much the entire League was mediocre, even Ash's last battle against Gladion.