1. Personally, I enjoyed XY, and although I liked Ash in this series because he was inspiring to others, and encouraged their growth(kinda like Yusei from YGO 5D's), but I also really hate some of the beginning episodes of SM even though they gave some good world building, it really felt as if the writers didn't know what to do with the characters at first because of the large cast? Either way, both of them have their flaws and strengths. I also like how SM is willing to tackle some sensitive topics such as death and being able to move on, in a way that doesn't really feel forced and really makes you care
People just have different opinions and tastes. That's all. Some are way too toxic and willing to push the other series down the other people's throats because they think that series is the best.
2. Paul. Easily Paul. Paul is the complete antithesis of Ash and pushed him in such a way that no other character in the show has before, by challenging almost every part of Ash's beliefs about what it means to be a Pokemon Trainer and how you should train your Pokemon. It was also nice to see how both of them, at the end of their rivalry, ended up learning a valuable lesson - people using different ways can still achieve the same results, even if you don't necessarily agree with them, and you should learn to accept those differences.
Alain's Charizard is so overpowered, and although he was one of the biggest reasons for Ash and Greninja working on developing their bond and the Ash-Greninja form, it just felt kind of pointless to introduce him as a rival to Ash, especially so late into the series. It would have actually been a lot better if he was introduced more early on in the series and been given more time to develop, but then again...
The rest of his team is kind of really EH. Unfezant was surprisingly strong for it's species, considering what Ash's and Skyla's Unfezant are capable of doing...Bisharp and Metagross are probably the strongest Pokemon on Alain's team besides Charizard, the rest are just there.
3. Go is someone who kind of represents a part of the fanbase, the people who got into the franchise through Pokemon Go and whose only interests are in catching Pokemon, and aren't really interested in trying the other parts of Pokemon out, like Mystery Dungeon, the main series, or the show. His philosophy goes along the lines of most of the Pokemon that he catches are just numbers to fill up for that Pokedex, and he doesn't even try to build bonds with most of them, excluding Raboot, since that's all they really are for him. Although with the current influence of Ash that he has on him, I'm pretty sure that he's going to start to change, and become more open and willing to try out the other aspects of Pokemon. Who knows, maybe he'll try out Pokemon Showcases or Performances one day
Oh yeah, I forgot to mention. He was a big jerk to Raboot, the only Pokemon he's bothered to make a bond with, by telling it as a Scorbunny that "he shouldn't try to do new things and give up"
