I like what I've seen of the main series Pokemon anime (the one before Horizons) but there is a hefty amount of said anime I haven't seen such as the Unova Region Saga. Having not seen those episodes, I am fully aware that I cannot pass proper judgement on them. But to be honest with you, I've heard a number of things about it that don't sound too good. Such as the leading lady among the main characters in that point of the anime, Iris.
A lot of things I heard about the anime version of Iris (I hear the game version is better) leave me with a feeling that I would not particularly like that character. If I go into specific examples this post will be too long, but I get a feeling a number of you know what I'm talking about anyway. As I said, I haven't actually seen the Unova era of the anime, but even so, I couldn't really help the feeling of being unimpressed with Iris from the claims I heard.
I also didn't really watch any of the anime past the Kalos seasons, so I only just recently found out about how in Pokemon Journeys, she became not only the champion of Unova, but one of the top 8 trainers in the entire world. That was a pretty shocking revelation for me. Either the negative claims I heard about her were exaggerated, or she really got her act together after the Unova seasons.