While Misty didn't have that much screentime and she could have been handled much better, they didn't make it look like she was such a strong Water Pokemon trainer in Kanto, despite using Goldeen to battle on land a couple of times, never doing much on-screen training and not having a vast knowledge of Water Pokemon. They're basically doing that with Iris in regards to her goal of being a Dragon Master. She already knows about all different kinds of Dragon Pokemon and basically has Dragon-whispering skills. Despite her lack of on-screen training, she is rewarded with Excadrill and Emolga listening to her, Axew learning Dragon Rage with very little effort and then Outrage out of nowhere in order to win a battle she clearly should have lost. And at the start of the series, she wasn't shown to be much of a strong trainer due to Excadrill not listening to her and Axew being pretty useless. Yet, they want the audience to believe that she won 99 battles in a row with Drilbur before she was old enough to officially become a trainer. That still annoys me along with the whole Outrage issue.
All of her accomplishments have been handed to her. She hasn't earned any of them herself through hard work. She a hypocrite and instead of people calling her out on her flaws, both personality and training method-wise, they are generally ignored and in some cases, such as with Axew's Outrage, they're rewarded. The amount of screentime Iris gets is the least of her problems considering how terrible the writing around her character is.