Don Draper is often considered the protagonist of Mad Men, but that distinction could also go to Peggy Olson. Mad Men covers many themes and ideas, but at its core, it's about the rapidly changing societal norms of the 1960s. At the heart of that theme (at least in terms of office politics) is Peggy's meteoric rise from rather disrespected secretary to dominant copywriter.
That said, Peggy is still very much a product of her time, even if she was a revolutionary and forward-thinking member within it. She still has many flaws that may not fly today.
Never Fly: Her '50s Style
Looking on the mere surface level, Peggy's original style would never fly today. Peggy begins the series in a very modest and somewhat childish dress. She has a ponytail, very short and bizarre-looking bangs, and a very conservative dressing style. Her style is often rebuked by the other women in the office, and the men often make fun of her squirrely appearance. That style should be left in the '50s where it belongs.
Fly: Her Ambition
One of Peggy's distinguishing (and greatest) character traits is her ambition. At the beginning of Mad Men, Peggy begins as Don's new and doe-eyed secretary, often not "getting" the work culture, nor Don's bizarre schedule. However, she quickly proves her abilities in advertising and quickly blossoms into the most ambitious character on the show. Ambition will never not be valued, and in that regard, Peggy will forever remain a character to honor.
Never Fly: Her '60s Style
As bad as her '50s attire was, her '60s outfits aren't much better. They were obviously quite stylish at the time, but therein lie the key words: at the time. Looking at Mad Men as a historical document, we can gaze in wonder at what passed as stylish in the mid-to-late '60s - often involving some time of loud, exorbitantly colorful clothing.
Fly: Career Woman
Another thing distancing Peggy from her co-workers is her career-oriented sensibilities. Peggy is very much a career woman, and it often comes at the expense of her personal life.
This is made the major theme of season five's The Suitcase, as Peggy sacrifices her personal plans to be with Don and work. She was a revolutionary figure in that regard, and even today, there is absolutely nothing wrong with favoring a career over a family.
Never Fly: Openly Condescending Attitude
Peggy is one of the smartest and most successful characters on the show, and she definitely knows it. Unfortunately, this self-knowledge often comes in the form of condescension. Peggy acts in a very condescending, pretentious, and superior manner towards her co-workers - often openly belittling them, their jobs, and their ideas. It's necessary for a boss to distance themselves from their employees (at least to some degree), but there's a difference between that and being openly rude.
Fly: Knowing Her Worth
As previously discussed, Peggy has a very strong sense of self-knowledge and worth. Sometimes that comes out in patronizing superiority. But Peggy's sense of worth is also highly commendable. Peggy knows exactly what she wants and what she's worth, and this often comes out in her fights with her mother. Her mother is very old fashioned and conservative, whereas Peggy is more independent and forward-thinking. And despite their constant disagreements, Peggy always stands her ground.
Never Fly: Drugs In The Office
It's no secret that some creatives use drugs as a form of inspiration. Peggy, despite all her virtues and grandstanding, often resorts to marijuana for inspiration - particularly throughout season five.
Openly smoking drugs in the office would never fly today, even in the most liberal and open-minded office spaces. The '60s were a very different time in terms of office culture, and that often meant drinking and getting high at work.
Fly: Giving Up A Child
At the end of season one, Peggy gives birth to Pete's child. Unfortunately, the '50s and '60s had a strong stigma of both abortion and out-of-wedlock pregnancies, and because Peggy wanted to retain her honor, reputation, and career, she was forced to hide both her pregnancy and her baby. Fortunately, those stigmas have greatly lessened in recent years, and giving up a child isn't the unthinkable act that it was over fifty years ago.
Never Fly: The Way She Treats Don
Don really liked Peggy, and she was great at her job. These aspects allowed her to coast on a rather unfriendly and hostile personality, and it gave her a pass where other, lesser employees would have failed. This comes about in her relationship with Don, as she often treats him with outright disrespect and hatred - especially in season 7. Granted, Don arguably deserves the treatment, but he is her boss. If anyone else spoke to Don the way Peggy did, they would have been out the door in seconds.
Fly: Flirting With The Counterculture
Even though Mad Men concerns the historical counterculture movement of the late '60s, it also seems to suggest that the "counterculture" is a far more universal desire for freedom. Everyone wants to "rebel" from the norm at some point, even successful, seemingly put-together men in their 60s. While Peggy doesn't go full counterculture, she often flirts with it in various exciting ways. Everyone desires some excitement. That's not beholden to the '60s.