There isn't some vast conspiracy to pay women less but there are many reason why women in general make less money than men. The most important ones, in my opinion being that women are less likely to ask for a raise, women are less likely to negotiate their salary, and women are less likely apply for jobs unless they feel they are 100% qualified. I've seen one or more of these traits in women I know in real life.

Women also take more time off of work than men for family reason. I'm extremely skeptical that everyone who has every hired a woman has looked back at the salaries for the men in similar positions and decided to pay the woman less just because they aren't a man.

Information on all these reasons is easy to google as well.

I'm sure there are real life sexist men out there, but I'm confident it's a very very small minority.

Personal example:

I (male) worked a company owned by two women which at a 90%+ workforce as one of my first jobs out of the military and I made more money than many of the other women. I also came into the position differently than them. I made many parallels between my military experience and new job, I emphasized how my other skills would benefit the company, and I was also freelancing in a similar role before I interviewed with them. I got offered what I thought was a modest amount of money and took it. Most of the other women in the office were fresh out of grad school, but lacked work experience and technical skills that I brought to the table and emphasized in my interview. So just looking at our titles it looked like I was being unfairly paid more, but in reality I leveraged my experience and brought more relevant skills to the table and did more work they couldn't do because of those skills. It just wasn't reflected in the original job offer or job title.

Then to expand on that, I helped two my friends get jobs at the same company and told them how to negotiate and what my salary was so they were able to get what I got or higher. So then two more men came in making more money than the women with the same title, but it was because they were savvy, had connections, and were coached, not because they women who owned the company valued women less.