People like Greninja's arc, what is awful is the conclusion and the fact that not only Ash lost the opportunity to have an actual mega, but is super-unfair with the already poorly treated Delphox and especially Chesnaught
Anime wise, Chesnaught had a focus episode albeit filler.
Typhlosion’s debut was in Hoenn and never appeared since it’s only two appearances in Hoenn. Chesnaught had one ep but was properly debuted and had proper focus.
that is not something propper of Kalos, in johto, unova, alola and even hoenn (swampert) the starters have received a bad treatment
Greninja’s arc is the definition of a great concept and execution that all came crashing down when Ash lost and then he released it.
I can see why one would think that the execution was flawed in one aspect in regards to the league loss, but I don't see anything wrong with Ash releasing it. That was an incredibly coherent and well-executed end to his character. I much prefer that to AG being stuck back on the ranch. Now that would just be boring and wouldn't have the kind of depth that Ash leaving AG to be the protector of Kalos with Squishy for a while had.
Because it shows that Greninja was the special one, not Ash-Greninja aka his bond with Ash. Even at the end of the next episode we can see it fighting against the plants without even needing its transformation.
Fighting the plants wasn't why Zygarde needed him, it was the ability to sense them, which was unique to him because of the bond, as the show made clear in the episode itself. Ash went on a diatribe on how their bond and power was built for that moment.
This is incredibly incoherent, but that's par for course. What do you even mean? Does Journeys Ash have to say that Greninja is protecting Kalos? It's literally mentioned in the episode itself.
This "protecting Kalos" plot doesn't add anything to either Ash or Greninja's characters. With other Pokémon departures like Charizard or Gliscor, or even human characters departures like May, the anime eventually addressed those events and eventually showed how much stronger they become, which is why those departures have a narratively purpose. Without this, AG ending is as bad as being sent to Oak/Kukui's ranch.
even though greninja is not released, ash still has his pokeball
Yes it does? Greninja leaving Ash to help Kalos is a fitting end for a Pokemon who once only fought and trained for himself. It shows the growth of Greninja and his bond with Ash with both being two intertwining characters whose development hinged on each other as their bond is now made use for a higher purpose, which was once again narratively built up before and executed flawlessly in the episode itself.
tbh I prefer it since at least it's a narrative reason why Ash isn't taking the pokemon that literally synchronizes with him to future regions.
So your logic is it hasn't returned so it's bad? What kind line of thinking is that? So basically you're saying the likes his alola and unova mons are also bad because they haven't shown any growth at all, and they've actually appeared so they must be even worse.
All of Ash's Kalos Pokemon bar Hawlucha had the personality of wet paper... Goodra sorta, sometimes had some, I guess