Even in AoU, she had...what, 30-40 lines? She was advertised far more than she was actually relevant. Mostly because, like Whedon tends to do, it was pretty much just jerking off Tony Stark (and Tony Stark's surrogate clone robot son) for the majority of the time, while still somehow failing to make the latter compelling or long-term relevant.
Fuck Age of Ultron. Ditto for the Natasha and Bruce bullshit.