Do you think having only One child is fair?

I would have loved a sibling. I'm 18 now and I think about the same thing; my kids won't have an aunt/uncle or cousins on my side, just one aunt from my fiance's side. I still think it would be awesome for me to have a sibling now, but when I was little, I feel like it would have been loads more fun. I found ways to entertain myself, but I would have loved playing with Hot Wheels with a little brother or playing dress up with a little sister.