While the same cannot be said for the games ( XY are one of my fav games but they aint perfect), i feel the anime was at its peak during the Kalos series. A more mature version of Ash, no lame childish jokes, darker subplots, shonen style, the XYZ special starring Alain ( much better than Horizons), the animation, the visuals, the music ( every Ash Greninja Transformation felt so badass).
This and Sinnoh were the only times I feel Ash deserved the league win, but well, it wasn't the case and well, Alola was pretty much a fluke. I mean Charizard falls asleep and Ash is eliminated so if Rowlet falls asleep, Hau should have gone through
And tho Journeys win was a happy moment, I feel it focused so much on Goh and like we barely saw Ash preparing much besides few world coronation battles so idk, it feels kinda like just plot armour, XY felt like he should have won
But yeah coming back on topic, they should have never made Sun and Moon into the childish mess it was. And XY series is indeed the series' peak