I think fandom tends to strongly misinterpret Nancy Wheeler's character as a whole, but right now we'll focus on the fact that drive for being a journalist is not because she wants to climb that job ladder to the top by any means necessary, but because she genuinely wants to use the medium as a means to help people tell their stories and be a voice for people who aren't being listened to/taken seriously.
Her first taste of investigative journalism was in season 2 when she was seeking justice for Barb, trying to find solid evidence to use so she could take down the lab for covering up the death of her best friend.
In season 3, she was the only person at the Hawkins Post that took Mrs. Driscoll's complaints seriously and followed up with what was happening even after she had been humiliated, laughed at, negged by her boyfriend, and fired from her job at the newspaper. Getting to the truth, helping Mrs. Driscoll, and protecting the town was more important to her than being popular at a job.
Again, in season 4 she was the only person who truly listened to Wayne Munson and believed that there had to be another explanation for what was happening. Every other reporter in town was more interested in selling the Devil Worshipper turned Murderer! headline, but Nancy treated Wayne with care and respect - because she knows that the truth is often something more complicated to be uncovered, and that the people involved are more important than simply an easy sell headline.
In closing, being a reporter may be Nancy's career path of choice, but she chose this path and sticks to it because of how deeply and personally she cares for being a voice for people who don't have a voice anymore or are otherwise not taken seriously - as she has been in their same position before with the death of her best friend. She cares about people.
