Having watched Clone Wars and Rebels in their entirety specifically after Ahsoka was being talked about during the Mando trailers dropping, I have to agree. The way some people talk about Ahsoka I was hoping for at least a fully realised character in that they grow and evolve over time, even if its just a little bit.
Her framing arc was actual garbage. I was hoping it was going to be her actually disagreeing with the Jedi Order, but instead it was a case of her being mad that she wasn't given a benefit of the doubt, despite choosing to run away in the first place.
And the betrayal from Bariss was shown no build up, nor was her friendship with Bariss even that much of a thing in the show, I can distinctly recall two arcs with them together, with Bariss some of those arcs being specifically about how Bariss shows no attachment to her master the way Ahsoka does to hers. And by having the friendship be undeveloped between these two padawans, it just lowers the feeling of betrayal. Anyone with a brain expected it to be her for most of the framing arc.
Outside of this, we don't see how Ahsoka seems to disagree with Jedi teachings. Anakin is her teacher but outside of being overly reckless in battle, we never see Anakin influence her thoughts on the Jedi as a whole. She just casually disapproves before following Anakin into whatever it is he does because he's her master. There's no sense of self-agency.
Even judging this character as someone who further characterises Anakin, I'm not that satisfied. And to be honest, it was all sufficient from the introduction of Satine, which explained why Obi-Wan wouldn't call Anakin out when he had his own issues. That Anakin's fall was ultimately caused by himself and his master. Ahsoka is a pointless third wheel.