On the surface, there is no reason why men and women cannot be friends with the other, as we all share the possibility of having things in common with people of any gender. As such, it is rational to believe that men and women can bond other these shared hobbies and interests. In fact, I think having a diverse friend group, with a mix of genders, is healthy for developing empathy for other groups of people.
Refusing to be friends with a person of another gender, based solely on their sex identity is frankly immature, and can lead to toxic behaviour. Not having female friends, if you are male can lead to a lack of understanding of problems women face. Not that I am saying that it is up to women to teach men, but it is easier for men to learn, if they have people in their life that can tell them of their experiences.
Similarly, the girls and I shared similar interests, such as reading, and using our imagination, instead of the boys who were obsessed with sports and videogames like Call of Duty. My girl friends were the only barrier to stop me from having no friends whatsoever. I think that this experience is shared by a few fellow members of the Alphabet Mafia, I have heard from many LGBTQ+ friends that they found it easier to be friends with the opposite sex, over their own sex.
For heterosexual people, it can be just as important to make friends with members of the opposite sex. For instance, you can go them for idea about how to ask a member of their sex out. Men can help women with what they think another man may like, and vice versa for women and helping men.
Platonic friendships between the sexes are very important to society, and I think that people today are beginning to recognise this fact, as I noticed throughout my life in secondary school, Sixth Form, and university, most friend groups have a healthy mix of the sexes in them. Obviously, some many lean more towards female, than male, or vice versa, but there is at least one friend who is a member of the opposite sex to the sex in the majority, within that group.
This makes a startling change to the attitude of our forefathers, whose friendships, especially in adulthood, were homogenous. Men made friends with men, in the world of work. Housewives made friends with the other women in the neighbourhood. This, in and of itself, is not negative. Everyone needs to have social interaction, but it is where the lack of a female presence in an all-male group can lead to misogynistic and sexist views on women being spouted.