Lol, I forgot about that image.
There was actually an episode where Ash's Pikachu fights an insanely strong Magikarp.
Also, not to imply X and Y isn't quality on its own. It is. But it has the advantage of coming after Pokemon Black and White.
The series that even hardcore fans don't like. Everything about Black and White felt like a step down from the previous series.
Ash regressed as a trainer, doing worse in this league than he did in previous seasons.
His team didn't develop, and at the end of the season, he had a bunch of undeveloped nothing pokemon. (His Snivy never learned a new move after he caught it.) Cilan's and Iris's respective goals were nothing, and as such, they never developed.
Ash had a bunch of loser rivals no one liked, and ultimately lost to
this nerd in the league.
The animation quality was all over the place, even though the series constantly reused the same animation.
The gym battles were uneven, and Ash rarely used any form of strategy.
Team Rocket got a powerup that ultimately finally led to Ash meeting Giovanni only for nothing to really happen. They don't even have a battle.