Musty is the best anime protagonist throughout all seasons. Best design, best personality, best pokemon (be it staryu and Psyduck alone) and at least she brings something to the table instead of those empty-shelled goodie-two-shoes after her. In the games, she is nothing special for being the second gym leader and all. In the manga, she is extra cool tho.
Cynthia is the most insufferable champion out off all regions. She is annoying in the games, she has a stupid design (a ballsack in her hair), the ugliest pokemon ever (garchomp) and was generally not memorable as an opponent. Whoever struggled against her is really bad at pokemon. Not helping that Sinnoh is generally the worst region to begin with.
Good point about there being a difference between the quality of a person's character traits and the quality of how a person's character traits are written. Cynthia hasn't been expanded upon nearly as much as Misty. Still wouldn't call Misty's friendship with Ash healthy, though that's probably as much due to Ash's immaturity as Misty's flaws.
As someone who fell in love with the atmosphere of Diamond (Music, graphics and all), Sinnoh is heavily nostalgic and its skewed type representation and slow-as-molasses HP animations don't tend to bother me. Not that I'm a massive Cynthia fan as a result (I don't tend to think as much about the human characters as about the Pokémon), but I just want to point out that Sinnoh being a horrible region depends on which metrics you're using (Atmosphere-wise, for example, Kanto would be the worst region due to the lack of culture, much of its soundtrack becoming recurring music tropes in later games (Meaning the score brings very little to the table if you've already played the other games), and generally being more bare-bones and repetitive in landscape features even in Let's Go Eevee) (EDIT: I've heard the Sevii isles have pretty great atmosphere and that Scarlet & Violet's world just feels empty with how easily you can avoid all trainer battles and thus all dialogue, so maybe Paldea is a worse region atmospherically? I'd definitely say Sevii-less Kanto is the worst atmospherically of anything I've played, which is most stuff before gen 9 except gen 5 (I rented out White from the library and played the post-game to transfer Pokémon from Diamond to Bank, and the atmosphere seemed pretty good from what I saw).
The ornaments in Cynthia's hair are probably meant to resemble Lucario's dreadlocks. As for the remarks on Garchomp, welllllllll... it's the sixteenth most popular Pokémon according to favorite (And eleventh according to six favorites) according to this survey,
, so most people probably don't feel the same way about Cynthia's ace.
As for Misty's Psyduck, yeah, it's an iconic Pokémon. One thing that I appreciate about the anime is how fleshed out most of the protagonist's Pokémon are as characters (With Misty's Staryu and Starmie being sad exceptions. I get that it's hard to characterize a faceless gemstone with arms, but why on earth didn't Misty call out her only fully evolved Pokémon in every major fight instead of leaving it imprisoned in its Pokéball for most of the show?). Psyduck's oblivious nature was endlessly entertaining, it's psychic powers made it seem unbeatable to my childhood mind, and it was funny to see how Psyduck and Togepi seemed to play on two different sides of Misty's character (Yeah, if I'm being honest, Ash was probably the least capable of the three to raise a baby Pokémon). It hasn't escaped me that Psyduck has been prominently featured in a lot of spinoff media, from Pokémon Concierge to random stuff like that random baking show and the Chinese video featuring all the video games that China... never... actually... got? Yeah, suffice to say that Psyduck is super iconic at this point (Now that I think about it, I'm not sure how much characterization Brock's Pokémon got. I guess we just got to see most of them more frequently than Starmie).
Thanks for sharing. Now I have a much easier time understanding your feelings on the characters in question. Hopefully I've done a good job explaining my feelings on Misty and on Sinnoh.