Twenty years from now, the majority of the population will be over age 65. You won't be lonely. The Benefit Package 1. Control of your life. When you have children, you lose a certain amount of control over your own life.
Children can have lots of problems.
You never stop being a parent. You'll have the time to explore parts of yourself that you never knew existed, because you'll have time to yourself. Insights about your life, your gifts, your talents, your desires, your interests can be explored. I'll take Katharine Hepburn's life any day. At any rate, whatever your reasons are for living childfree, the decision is, of course, reversible anytime you wish.