You could have mentioned Under the Skin, Lost in Translation, Ghost World, Vicky Christian Barcelona, Match Point, Don Jon, The Prestige, even her mere voice work on Her, but instead you reduced Scarlett to her role in The Avengers as a mean of belittling her. Sorry, but your ignorance is shining. She's no Denise Richards. Hell, she's not even a Jennifer Love Hewitt. If Scarlett "cheapened" celebrity, then she wouldn't have lasted. Even the prettiest actresses without talent don't last. They are relegated to scraping for network/cable television roles, or starring in B-movies, or they simply outright disappear altogether. These days that breed could probably get some "accidentally leaked" sex tape work.
Not Scarlett. She doesn't need it. Why? Because she can act. Flat out. The girl has chops.
Furthermore, she goes beyond that. Scarlett is really the closest thing we have to an actress carrying Marilyn Monroe's torch as the defining seductress of her generation. She's the first person in history to win Esquire's "Sexiest Woman Alive" twice. She's in People magazine's list every year. She's probably won more major awards like that than any other living woman. That alone reflects that she possesses an extremely special, goddess-like trait justifying her transcendence to "celebrity" status.