In today's world there's more than two genders and more than three sexualitys, I'm totally accepting of anyones prefrences and will always call people whatever pronoun they prefer. But occasionally I feel some genders and sexualitys are just extra and unnecessary?

For example people who are demi sexual, I wouldn't class this as a sexuality along the same lines as bisexual or homosexual but more of a personal preference?

I understand that this may be an unpopular opinion, but if someone could clear it up that'd be cool.