I read an article not that long ago that came to the exact conclusion I have written as the title of this and while I was reading it I was thinking that for most people, this is obviously true. If you were to ask just regular people, who are not MMA fans to name ANY female MMA fighter I think most people would recognize Ronda's name, but would really struggle to name anyone else.
Hell, I watch almost every UFC event that is televised and read a lot about the stats and what not and I would struggle to name 10 female fighters from any point in time, I would really struggle to name 10 active female fighters.
There was a time there when Ronda was such a dominant fighter in her category that the UFC was kind of running out of people for her to fight. Ultimately I think that this is the reason why she fell from her position at the top. It became a bit boring to her so she started to mix up her fight styles to make the bouts more interesting for her and the fans and this was her downfall. After losing 3 straight fights Ronda quickly left UFC and MMA in general, despite the fact that she was getting paid a TON of money to lose fights. Even in her losses she was immensely popular with the fans and there were a lot of reasons why that was the case.
For one thing, she was absolutely dominant in the women's division. Most of her fights would be over very quickly and this mostly came in the form of getting in close to her opponent, swarming them, taking them to the ground with a Judo flip, then pulling an arm bar. This happened like clockwork in most of her fights and it started to be a question not of "if" but of "when" this was going to happen. From a Vegas odds point of view it was assumed she was going to finish her fights by submission in the 1st round.
Another reason why people gravitated towards Ronda was that she was not just a dominant fighter, but she was also quite pretty.
I'm not saying that all the other fighters are ugly but let's be honest here: More often than not fighters are not very good looking people in the men or women's division of the sport. The men in particular have "cauliflower ears" and that's not a good look for anyone.
Ronda also seemed to be a genuinely nice and intelligent person and the fact that she had no political agenda at all made her even more enjoyable.
There was a famous press conference that Ronda was a part of and some feminist blogger or something tried to rope Ronda into an "equal pay" discussion that Ronda quickly shut down in a direct, yet friendly way. She pointed out to the reporter that her situation is like this
"I think how much you get paid should have something to do with how much you bring in, I'm the highest paid fighter not because Dana and Lorenzo wanted to 'do something nice for the ladies'. They do it because I bring in the highest numbers. They do it because I bring in the most money. And I think the money that they [female athletes] make should be proportionate to the money they bring in."
The crowd in attendance applauded this answer and it is still revered by people like me all around the world because it is just such an obvious thing and other women athletes fail to understand this. The reason why professional women soccer / football players and WNBA players are paid far less than their male counterparts is because very few people are interested in seeing these events. Ronda set the record straight in one paragraph and she did it in a funny and friendly way.
Even though Ronda's exit from UFC was disappointing to a lot of people, you can't argue that the number of people interested in the women's divisions diminished rapidly right after she was no longer part of the picture. However, there are still a lot of people that look forward to the women fights even if they are mainly watching because of the fights between the men. If it wasn't for Rousey, the women's division might not be on major events at all. She propelled the women's division to the "front lines" in a way that no other woman has ever been able to do. In a way she forced the door open for all the female fighters that are prominently featured on cards to this day.
Ronda is not the G.O.A.T. in women's MMA though and I don't think that she would argue this either. What she was though, is someone who is one of the most memorable fighters in the history of UFC in either men or women's competitions and I think it is safe to say that the spotlight wouldn't be on women's competitions in UFC or any other MMA promotion if it wasn't for her dominating the sport when she did.