Representation is important because it reflects how we view people and it shapes the cultural norms we have as a society.
What happens when there is no female representation is that the male perspective becomes the norm and the female perspective the exception, that is, the value of women is diminished. Therefore value is determined by culture.
We see this on board many ships. There are very many women who feel that they have to prove their competence before they are accepted. They feel that most people have no problem with the fact that they are women as long as they show that they are good at their job.
After a lot of messages and comments from women around the world, my understanding is that this becomes even more evident the more stereotypically female you look. To back that statement up with some research, there are studies from the US that show that when it comes to men, looks don't matter in how likely people are to think he is a scientist but the more stereotypically female a woman looks, the less likely people are to think she is a scientist.
What would have been the results of such a study in shipping?
Other research shows that female students do better in science when there are pictures of female scientists in textbooks?
One can imagine that this applies to most types of education.
If we look at a slightly more practical level, a 2009 study by the women's engineering society showed that 74% that all protective equipment is designed for the sterotypical male, which incidentally far from all men look like. A 2017 TUC report showed that the problem of ill-fitting protective equipment is worst in the rescue sector where only 5% said that their protective equipment never hindered them at work. And as part of the crew on board a ship, protective equipment is something that some more than others will become very familiar with.
To summon it up, female representation matter.