Did you ever want to be an only child? I never did, but most only children say they loved it because they got everything they wanted and everything

No, it would be so lonely, growing up I didn't have to make much effort socializing because I already had someone, my sister is just one year younger so we've always been close. I can't imagine growing up playing on my own or not talking to her before sleep or doing everything with just my parents and having to meet other people outside our home setting in order to feel company.
And I know people who grew up without siblings but still aren't spoiled at all and never thought the world revolves around them. Although I noticed they tend to be quite jealous of their friends, like if their friends hang out with others and feel more entitled to people's time (at least that was my observation as a child but of course it changes once they grow up).