Well think of it this way. If you joined the army and instead of doing what the job description implied you were forced to retrieve coffee for your boss, adjust things in his room because he's too lazy to do it himself, forced to endure constant sexual harassment to the point where your boss is physically touching you and groping you, occasionally even raping you. in addition to all of this you are paid less than people who do less work than you, even if you work for years you will not receive a promotion while others will receive promotions for doing much much less work, you're paid significantly less, and if you ever speak up or talk about this you will be at risk of being fired.

I took a gender studies class where they talked about it and showed a documentary. I remember they did an interview and one of the secretaries was told to get up and come into the bosses offices just so that she can take a calendar off the wall. I can't imagine doing work where you're basically put into a maid/servant to do basic tasks for someone who doesn't want to do them himself in addition to the sexual harassment

I learned about it recently and looking around I saw people talking about it as just the simple "I work 9 to 5" words. I don't think many people appreciate and know the history behind it