Partially an appreciation post for Zoey. DP with very little argument had the best rivals of the series(sans personal opinion) but I think of the two main ones Zoey is underrated.
Paul is great in that he gives a motivation to his rivalry with the ideological clash as well as abandoning Chimchar. I do however feel that this is really all Paul has going for him in being Ash’s shadow. His rivalry with Ash didn’t have as much impact on himself as it did on Ash with mostly his losses against Brandon and Cynthia that got him to reevaluate his training methods. Though it is satisfying to see him slowly start to respect Ash.
Then we have Drew who arguably laid the groundwork for both DP rivals. He, due to contests having multiple direct matches, had much more interactions with May than any of Ash’s prior rivals. Plus thanks to Ash not having any recurring rivals in AG he really gets to shine as being a notable rival. While he antagonizes May to some extent he is shown multiple times to be a relatively good person helping May or her friends occasionally. That duality really helps fit the rivals not enemies role. Also because Advanced crossed both Hoenn and Kanto we did get to see May lose to him in a climactic match and win in a climactic match making it satisfying to see May’s development as a coordinator.
Then we have Zoey who is (to my current knowledge) the only rival to accomplish her goal within her original series. She provides a great contrast to Paul being a purely friendly rival rather than an antagonistic rival. Going a step further than Drew and actively helping and supporting Dawn with her coordinating. We see a couple times how she isn’t perfect with her losses to Nando and May but she remains a challenging obstacle for Dawn. As well as her own relationship with a best friend of hers in the form of Candice a they way they develop their parallel dreams. To top it off she, like Alain in the future, remains undefeated in a tense match against Dawn. I’d say her only and possibly fatal weakness as a rival is that she only went head to head with Dawn twice…
Even if you disagree with Zoey being the greatest rival in the anime you do have to admit she is the greatest friendly rival in the anime. I do also have to note that both Zoey and Drew benefited from essentially sharing their runtime with Dawn and May respectively compared to Ash who changed rivals which in turn solidified Zoey and Drew as arch rivals.