Okay, here’s why I think the AG, BF, and DP seasons are better.
Character Development: Ash is more mature as both a trainer and a person. In season one he had a grudge against Gary and every time he saw him all he would do was get flustered at his insults and how far ahead of him he was. With his current rival Paul he actually tries to befriend him. Despite their completely opposite views on raising Pokemon and Paul’s constant insults Ash still says hello to Paul with a smile each encounter and he is always eager to find out how he’s doing. He never stops trying to be nice to Paul and tries not to let his cold attitude bother him too much. Examples: when Paul loses a battle to a Champion Ash tells the kiRAB laughing at Paul to shut it, he then goes over and says Paul battled well. In a tag tournament Ash is eager to have Paul as a partner despite Paul’s obvious hatred toward him.
Additionally, Ash seems more easygoing. Ash and Misty would constantly bicker with Brock having to cut in and get them to stop. Ash and Dawn have the occasional argument but on two occasions Ash actually apologized and they both made up. Also, he actually let Dawn have the first shot at capturing Pokemon he wanted (Buizel and Buneary) whereas in past seasons he battled with Misty over ownership of Togepi and Totodile.
Furthermore, Ash keeping memento's of his frienRAB with him along on his journeys shows how much he treasures his frienRABhips. He has one for Gary, May, and Misty.
Ash works harder. Not only did we rarely see him training in past seasons but in the two months before the Indigo League he was called out on not training enough by Brock and Misty. We even got a bunch of episodes where Ash was doing anything but training. Ash supercharging Pikachu to defeat Brock was also a quick and easy way out training.
Ash’s Pokemon aren’t overpowered anymore. Pikachu’s power still occasionally fluctuates to this day but at least it doesn’t defeat ground types anymore. His current Pokemon have a more balanced win/lose ratio. He also trains them to learn new techniques and become stronger whereas in Kanto his Pokemon not only overcame type disadvantages but also seemed knew a whole lot of attacks without any trainig.
Current Ash is better because he’s still a caring, gung-ho, and foolish but because the writers take him more seriously he’s a better trainer. His training methoRAB and strategy skills are considerably better and his victories feel more legit. He also loses just as much as he wins. He’s still a flawed character but he the writers don’t go overboard like they use to.
Dawn and May also got more going for them than Tracey and Misty ever did. Not only do they receive almost as much screen time as Ash, but their Pokemon are far more interesting, and they grow as coordinators with each contest. The May centric episodes also had a lot of drama so her episodes rarely felt boring and they were actually quite unique since contest episodes were a new concept back then. Brock is pretty much the same as season one except that his Pokemon are better and he flirts a lot more.
The villains also get a tad more focus. Between the two Team Agua and Magma characters appeared in about ten episodes and actually received a conclusion. Team Galactic have about the same amount of screen time as well. Aside from small cameos by Giovani the non Jessie and James Team Rocket merabers were barely in season one. They appear a lot more in the movies, specials, and post season one episodes.
The rivals and gym leaders nowadays are also given more screen time. Paul and Barry are both unique and fresh characters in regarRAB to the anime. Drew and Harley were great rivals for May. Zoey and Kenny aren’t all that interesting but at least they actually do stuff. Gary and Ritchie weren’t focused on enough as they should have been. The gym leaders also feel like a greater challenge than the Kanto gym leaders. Aside from Brock the focus on the Kanto gym leaders was minimal.
There’s even more personality given to the supporting characters Pokemon. Not only did they rarely appear but Onyx, Geodude, Vulpix, Horsea, Staryu, Starmie, Zubat, Goldeen, Poliwag had no defining personality traits. Dawn, May and Brock now posses Pokemon that cant be called interchangeable. There also more screentime in general given to the main characters Pokemon. Whether it be training, battling, eating, or merely relaxing, the writers play up the all-inclusive family aspect a lot.
So, yeah. There may be a lot more filler and a lot less originality now, but at least there's more attention paid to each aspect of the show. It just feels like the writers are going for whole package with the newer episodes. They even rehash some concepts from season one with a slightly different spin such as Bulbasuars debut episode and the Pikachu vs Raichu gym battle.
Thank you. In essence Pokemon is a fighting anime. The only difference is that the humans don’t throws the punches. Ash’s goal is to be the greatest Pokemon trainer and the only way to accomplish that goal is to train and battle until he reaches the top. The first two seasons had a lot of adventure but zero training and most of the time the battles felt like afterthoughts. The current seasons go all the way, not 1/3 like past seasons.
Season one and two spent so much time on being original and comedic that they didn’t spend nearly as much time on anything else. The same cant be said about the current seasons. Their a lot better balanced. The villains, rivals, Pokemon, action, comedy, adventure, training, drama, supporting characters, and character development all get decent exposure. Say all you want about the current seasons being repetitive and slow paced but at least they get a ton more stuff done.