But I'd also rather we just do away with the concept of gender. Sex is a thing, and is also non-binary. But "concept of gender" is something strange altogether.
Presumably the only reason for having it at all is that advertisers assume they need that information. In which case, 'Male', 'Female' and 'Other' would suffice. It's a pretty safe bet that if you don't identify as simply male or female, advertisers aren't going to bother caring about how to advertise to you.
I'm sure it serves other purposes too, even if they are as simple as displaying your sibling as "brother" vs. "sister", or your brother's children as "nephew" vs. "niece".
But I'd also rather we just do away with the concept of gender. Sex is a thing, and is also non-binary. But "concept of gender" is something strange altogether.