>>14716736That's because she's the only Gym Leader who did anything the entire fucking game.
You battle her 3 times. Run into her a few times in the game world, she gives you a Lucario and the megastone for it, and she passes on the secret of Mega Evolution to you.
Hell, she got more development than our latest Champion Audrey Hepburn.
Who was by far the worst fucking Champion in the series by far.
Blue? Development the entire game. You and he develop alongside eachother.
Lance? You interact with him in both Gen I and Gen II frequently.
Steven? Right there in the thick of it with you in your battle against Magma/Aqua
Cynthia? Encounter her throughout the entire time. She gives you useful items, helps you along, gives advice and words of wisdom, and genuinely has the air of a Champion about her.
Alder? Encounters him throughout the entire game, he does the same thing Cynthia does, and yet again in in B2/W2 even when he's no longer Champion.
Iris? Exposure on par with Lance, but still enough to make her relevant as Champion.
But holy fuck, how many times do we see Diantha before the Championship?
Twice?
And she says all of two words.
All we know about her is that she's an actress. Fucking amazing. 10/10 Champion.