>>42634502A lot of people here clearly have not played the games or have but skip most of the dialogue. It is explicitly stated that Leon and Cynthia are child prodigies, having both become Champions at ages mirroring the protagonists, and having kept their positions until the MC eventually defeats them.
Comparably, Steven is also one of the strongest Champions, regularly noted as an extremely powerful wandering trainer who only stepped down from competitive battling in order to continue looking for rare stones. Steven asks Wallace in their conversation at the end of the Delta Episode to take his position in case he decides to go on a journey again.
Iris on the other hand is at a lower tier than those 3, who can without a doubt be labeled the Top 3 Champions in-lore. Iris didn’t have to do a Gym Challenge, or compete in the Pokémon League, she was specifically chosen by Drayden due to her budding skills as a young trainer and was trained by him in order for her to become his successor. Alder knew Drayden was looking for a successor and after his lost to N he was fazed, so he sent the challenge letter for Iris in hopes she’d be strong enough to take over. She’s definitely talented but not nearly as strong as the others because she doesn’t have as much experience.
Champs like Lance and Wallace are strong but hold no candle to the ones listed above, as they are just stand-ins for the real Champs, i.e Red and Steven, who left to go on journeys.
Diantha is Champion in a region with much more qualified trainers that she herself acknowledges. That alone tells you enough about her qualifications.
