This entire thing is subjective, and at the end of the day it comes down entirely to whether or not the writing in the games appeals to you. I'm guessing for you, it does. Me, though? If they're going to push these NPCs repeatedly, I expect them to be able to justify that with quality writing and character development. The sole thing that sticks out for Pokemon NPCs, to me, is design. None of them have even a shred of identity beyond what they look like, and when they reoccur continually and that
still happens, it gets worse. It shows just how little thought was put into them. You can throw as many examples of change as you like, but it remains that all you're seeing is the beginning and the end. How they started, and how they end up. You never see the middle. How can you have development without those transitional stage? People don't just change. They might as well be two different characters, because the only thing that links them together is their design. Oh sure, they show up throughout the game, but all that changes is their Pokemon. That's not really development for them as characters.
Line up any number of different characters from the Pokemon franchise and you can probably name them easily enough. But take some quotes from some of their lines in game and see how many you can name. They have no defining, standout moments, or clearly defined personalities, outside of that aesthetic design. They're just hollow shells with more than 2-3 lines of dialogue, and that is not necessarily a good thing. If Pokemon needed that, the franchise likely would have never gotten off the ground, because it never used to have it.
You don't need to know anything about a character's backstory to appreciate them, no. But they disappear, and then they come back with a marginally different tone to their dialogue, with no explanation for how that happened, and they never show it.
Show, don't tell. That is key to good writing, and good character development. When have we ever actually SEEN these NPCs develop as characters? Even Lillie, who appears more often than any other NPC in SM, never SHOWS how she's changed. Just tying your hair back doesn't equate to character development. And for Gladion? Just having one of your Pokemon evolve doesn't equate to character development. GF don't have a clue what good writing is, and it gets more and more obnoxious with each passing generation.
And here is the thing - no, it's not really your journey anymore. You play as a character, but they're not important to the story; they have no personality whatsoever. Gone are the days when it was just you vs. whatever, and that's not necessarily a bad thing...but the ones who star alongside you have no personalities and no character development of their own. They show up at important times - or in the case of SM, all the bloody time - with nothing to show for it. You don't need to know anything about their backstory, but you DO need to know something about their lives, and their personalities, rather than just quick flashes of dialogue followed by battles or whatever. That's not storytelling. It's intrusive, it's lazy, sloppy, and bad writing. Again, show and don't tell. Telling us these characters have changed is not the same as showing us how and why they've changed; getting us involved in their story - which is clearly what the games focus on now; SM was almost entirely about Lillie and nobody else - and getting us to actually care about them.
Really, the two approaches are difficult to compare, as the games have gone from a vaguely open-world make-your-own-story approach to an almost on-rails traditional RPG approach. They're severely lacking in the latter because of the writing. I realise that is subjective. But I think my points still stand and if you played any other RPG series and gave them characters like Pokemon has, it'd be hailed as an absolute disaster for the poor quality of the writing and the fact that nobody is memorable outside of their designs. They have a VERY long way to go before they can deliver a quality story-focused experience, and I don't think there is anything remotely praiseworthy about the characters as they are now. The games aren't enjoyable because the quality of the writing is mediocre at best, and that is what they're drawing all the attention to by shoving these NPCs in our faces rather than leaving us to our own devices. It's a valid approach to take to games. But until they improve the franchise will never be as good, to me at least, as it was in the days of Gen IV. Because they can make a good world with good gameplay, but they just cannot make good characters.
