I think a bigger problem is how much time the writers devoted to her plot this season. She's come exactly nowhere from the girl we saw murder Trant at the end of the last season. Sure the street-play stuff was fun, but her character has been spinning her wheels for a while now, seemingly for no reason.
The show is attached to her in the same way they are Dany and Jon and Jaime. Even when the plot isn't there we're forced to check in on them seemingly every episode. I understand this, her character is popular and I can only assume they believe that cutting her screen time back would have a negative impact on the show's viewer-ship. Not sure I agree with that sentiment but I understand it.
So yeah, the real problem here is how much time they've given a character who's basically had nothing to do for the past year.
Also Arya isn't the hero the viewer-ship believes her to be. I can't understand why I keep seeing 'Fucking Yes Arya' on social media. The girl is at the very best broken. She's gone from wanting revenge for her fallen family to actively enjoying the taking of ones life. That's the angle I hope the show goes down next season, less wishy washy hand waving and more character beats about what Arya has become, or is about to become.