If she had stayed human, I'm not sure how the movie would've been able to help with her character development. She's still the same character as she was as a human but her frog form helped her to develop and learn her lesson. Besides, what would be her reason to help Naveen if she stayed a human and the kiss didn't work because she's not a princess? Her being a frog helped add more of an urgency to her motivation.

Making a PoC person a animal the majority of the time just seemed like a rip-off to me. Just let her stay human, that's how the original story went anyway. It's just super disheartening to look at a frog during the whole movie as "representation." It'd be nice to see something that cared a little bit more about the character it was trying to convey. I'm fine with her being a frog as is, but honestly I would love it if she was just kept a human.

I love animal movies, but I lost interest in this movie after Tiana turned into a frog. I'm sure they could still have come up with a better story if she had remained human.

kinda will have changed the entire storyline