But , The main cast of Pokemon changes with every series ! Ash , Pikachu and Team Rocket are the only original character left while Misty & Brock are totally disappeared from the anime.
Not only that , Characters from "Timeless anime" never change their personality ! Their personality never develops or improves .
I think constant cast replacing did more harm than good long term.
If anything by replacing so often main characters you killed chances of having stable cast in who people could invest emotionally wanting to follow their growth and see where will work and journey take them being used to full potential.
Continuity became nonexistant duer to constant soft resets happrening with Ash abandoning all past pokemon and previous friends who are almost never brought up ending forgotten. As well being killed any chance of having consistent, plot driven story which evolves and changes over long period of time thanks to revamps.
Reflecting negatively on Ash development and journey as well. Because of lacking stability in cast, continuity in form of another familiar face through which people could relate and associate anime with along with having on going plot which keep its bounds with previous sagas adding to credibility and amount of growth characters experienced until now.
In other words lacking characters whose history spent with Ash, past experiences, development and close friendship would be carried over to new generations allowing for consistent following , more compact plot and establish of loyalty among fans preserving show popularity.
Show with stable cast and strong continuity creates brand around themselves and loyal viewers , while at same time attracting new fans toward it becoming interested in characters and storyline who still didn't went into it.
Something pokemon doesn't do, but other long lived shows such as One Piece, Dragon Ball, Fairy Tail, even Digimon in not forgetting about its roots and past actually does.
However Ash personality changed a lot from original series ! Even AG Misty's personality is totally different then Original Misty.
Most fans claim that Misty become more develop and mature ! Thats the main problem with it.
You see , The more A character mature , The less funny he/she becomes!
Mature characters can be just as fun as immature ones. Misty matured in some aspects as result of character development, but does that mean she is collected and rationale over everything?
Not really.
If there was any reason for you finding Misty less interesting than before, problem wasn't her personality and behavior. But circumstances and situations in which she was written not interacting with enough memorable characters to allow her persona traits to come to expression. Lack of screentime dedicated to Misty in episodes or lack of attention on her goals, dreams and interests to shine in her own light.
If there was anything in what Misty changed was that she became less violent.
But was that bad thing?
I wouldn't say, because in Hoenn we saw Misty portrayed as smart, resourceful and strong young female.
Being much more confident and independent, real badass in battling(especially when shocking everyone with that Gyarados)while showing lot of that sassy, defiant attituide being tough and taking things on her own when scolding Daisy and taking care of Max. Along with more of her feminine charm and playful, quirky side when asked for date, going crazy over bugs and embarassing herself with Psyduck bringing herself in trouble due to being at times impatient.Acting like someone in early teens being more selfcritic and responsible mixed with sarcastic, fiery demeanor in defiant kinda way.
Still being enjoyable and fun in different way.
Oh please , Misty & Brock were always at the side role ! Its was their interesting personality that gave them the spotlight.
Truth is , AG Misty was so nice and Polite that she didn't felt like the real Misty ! I remember and love this Misty--
"Because Misty in AG wasn't irritated by Brock firting coming up with sarcastic remarks and pulling him by ear."
"She wasn't mad at Ash for acting rude snatching invitation to festival from her or didn't scold him over embarassing himself infront of King."
"We didn't saw Misty playfully teasing Ash about his skills as trainer or resourcefulness with Ash reciprocating back.
"Because we didn't saw Misty in AG being angry at colonel Hanson yelling and acting all fiery and brash."
"Being upset and frustrated over Daisy rushing her back home."
"Found bugs disgusting as always causing that she and Max fall of the cliff running panickly away."
Etc, etc.
Oh wait. We did.
Now i know some wanted to see Misty getting in catfight with May. Or slap around Max like rattle. (I didn't).
But reason why there wasn't any hostility or tension is due to Misty not having reason to be snarky, explode or be intrusive toward most characters there. With May actually admiring Misty and how tough, fiery and competent she was. Max being friendly and admiring, Brock not doing anything excessive and eccentric in haf of episodes for which Misty returned in Hoenn etc.
As well purpose of plot calling for something else. Such as in Max case with Misty serving role as bigger sister, role model to him. Helping him to reconcile with May fixing their brother-sister relationship. Showing through her own example how to stay cool and tolerant in some situations not losing head(with Max complimenting on how manageable and brave she is) and teach him valuable lesson about family relationships and their importance.
Being for that reason more calm than let say in Togepi episodes for example or chronicles. It was actually appreciating to see other sides of Misty character showed and how compassionate and responsible she can be as well complimenting nicely her more temperament, arrogant side. More sides and traits someone has to its personality; deeper and more nuanced he is.
Misty acted completely in character there still having her charm, fire and quirky nature.
But whether someone will "show its teeth"(metaphorically speaking)and be incondsiderate, agitated also depends on:
-storyline and plot circumstancdes
-other characters which surround you and if they will give incentive, reason through their actions for such behavior.
This determines everything as far as dynamic and interaction between characters in story goes.