There's also the fact that things being made for men is so normalized that nobody bats an eye if a video game or movie only has prominent male characters. Society often treats such works as if they were gender neutral. But if you create a work that's all women, society tends to treat it as "for women only", toxic masculinity often treats such works as a no-go for men, and many people are much more critical towards them.

It doesn't even have to be as blatant as all characters being the same gender. In general, society tends to default to male dominated everything and can often even view being 50/50 as "women are taking over".

Even on the internet, people tend to default to male pronouns. Or when giving a hypothetical, they tend to default to male characters.

All these kinda things lead up to media that also skews for men.