The repetitiveness can be annoying but I guess what I don't like is re-showcasing of pokemon.
There are filler episodes with a specific showcasing of a pokemon. I find it annoying if there's ANOTHER episode with the SAME pokemon being showcased.
Of course it's nearly impossible to have equal airtime on the pokemon, and some have to have more spotlight and others shafted, but on pokemon that the main characters don't have, it seems biased to have re-showcasing when some pokemon haven't even been seen as much.
Ideal overall showcasing would be like dude, we saw that pokemon already showcased, we've seen it win a battle, we've seen in lose a battle, and we already know it's classified as Legendary/whatever it is (this example leads to Windie. This can be an exception because it managed to be shown several different ways. However, another airing of it would probably cause a repetition.)
Oh and it's probably preferrable to not have a showcase of pokemon power from team rocket blastoffs. That's not really showing power, as apparently pokemon of any type of experience can launch them.
Team Rocket is alright, but they should have different ways to present them. Actually most non-typical Team Rocket circumstances have actually been interesting to watch. Or, present a different way to get a solution, or actually have them win a bag of food or something if the pokemon really aren't supposed to be stolen that badly.
Oh right they need power balance too.
And personally I never like Satoshi's tournament losses since they all felt like all the conditions it was possible for him to win (or that there was imbalance, or too much one hit KO, or too much back and forth, or something else). It either felt like the condition of losing was conditional, disadvantageous, bias, or promotion. Perhaps I don't like to watch over 150 episodes and go through many pointless fillers to see Satoshi end up losing anyways.
Satoshi had great wins that were exciting to watch. The losses don't have the same feeling (though that merely could be win/loss differences), but all the losses don't seem convincing. Credit to the other trainer, but at best it looked like the opponent had a 50% chance to win. Actually Satoshi wasn't really even in losing conditions.