The reason I am childfree is starting to not be for me anymore.

More and more I see the lack of children as a positive thing for society and I want that to be the reason. I want to feel like I'm doing the right thing for the planet even if it doesn't really feel like I am. But the truth is the real reason I don't want kids is it would ruin me. I'm not capable of raising kids. I don't really want babysit. I don't want to have to worry about someone else. I want to be able to do what I want when I want. I feel like I would fail as a parent. I like being lonely. I don't want to ruin someone else's life, even if it would ruin mine. Why is this not a good enough reason? Why should I have to lie about why I'm not having kids?