I speak Italian, which works similarly to French. The male form is called the “non-marked” form, while the female is “marked”. It means that if you use the female form, you’re actually talking about women, otherwise it may be anyone. So, the real inclusive form would be to just use the male form.
It’s because both Italian and French come from Latin. Latin used to have three forms: male, female and neutral. The neutral and male form were very similar, so during the evolution from Latin to modern languages, the two forms collapsed into one.