Gender is a social construct, it can be useful for some people and not for others, that's why non binary exists. Some people feel more comfy with gender, some don't. Some people have an easier time understanding themselves with gender, some don't.
We don't need to, and shouldn't just disregard gender, it's important. However, if you don't feel like you need a gender, you don't needa have one. Non binary folks are completely valid, but people who misgender others bc they don't beleive in gender. Don't be one of those people.