the issue I keep coming back to, and ultimately i think an issue that can't be resolved without putting in new mechanics, is that pokemon still have no real agency within the story; a pokemon is rarely ever a character - that is to say, pokemon aren't given motivations or take actions that impact the progression of events. they are entirely passive.
as much as PLZA gives texture to the pokemon by adding the dimension of time and movement into battles - the primary mode by which we engage with them in any given pokemon game - pokemon still mostly serve as plot devices. ogerpon is, to date, probably the only real example we have of a pokemon who is actually a character within the context of the games.
and while the games continue to insist that the bond between humans and trainers is super important, the pokemon still mostly feel... largely unimportant, narratively. what pokemon we have don't matter outside of the confines of a battle. what our pokemon like or dislike doesn't matter beyond how it influences a battle (berry flavors and natures). we barely even get to interact with our own pokemon outside of battle anymore without contests, without the pokeathalon, without pokemon-amie. I can throw a ball for my pokemon to catch. i can't even pet them!
and then on top of that, the mechanics driving the narrative forward is battles and only battles; whatever problem the protagonist is faced with, the answer to it always has to be "and then it's defeated in battle, the end." there is one singular hero who is the strongest, and the specialest, and they're the only one who can save the day. them, not their pokemon, because the pokemon they bring don't *actually* matter that much.
which is ironic, considering how hard gamefreak seems to be trying to escape from the old "pokemon is so fucked up, you force them to dogfight for you." it feels like there is a hesitance in PLZA (and, frankly, everything back through Sun and Moon to some extent) to acknowledge that humans might be just as dangerous to pokemon as they are to us, or that humans can be dangerous to pokemon at all. it presents humans as a completely neutral party, or even just an Objective Good for literally everyone, except for a few hiccups like "guy makes a time machine," and even then... those are presented as the exceptions and not the rules!
as the games go on, our pokemon manage to have less and less identity as anything other than tools for battle. how do humans relate to them? how do humans understand them? by battling. and battling. and battling. and battling. and battling.
and while in and of itself, that's not bad - it kneecaps the narrative in a pretty significant way, i think, when it tries to tell a story about anything other than "the one specialest strongest guy who will save us all by being really good at battling and absolutely nothing else matters". the ending of any given game MUST be that the protagonist defeats the Final Boss in a battle. so the game must have a final boss. the conflict must be solved by defeating a singular entity. the protagonist must be the one to do it.
and when the game is about, say, the future of a city full of people with different ideas and goals and dreams, and how are we interacting with pokemon, are they happy, how do we protect them and ourselves, why are they doing what they're doing, what do they want from us, what is the right thing for us to do in regards to all of this -
having the resolution come in the form of "and then you beat the big scary Boss Fight that was causing Problems, the end!" makes the ending feel arbitrary. nothing was really resolved here; things just stopped happening.