Whenever theres discussions about child free Vs parent lifestyles though, the young child period is so disproportionately heavily weighted
And as a parent who is long past that period, much as it felt endless and vast at the time, it was really such a short episode in our lifetimes (unless you have 20 kids!)
I think this when things like happiness is compared too.. are they comparing parents of 30 year olds to child free couples?
Financially YES you plan differently and live differently even with full grown adults children, but sex? Bodies?
Are we really claiming that childbirth is the only thing that ages a body, and child free 65 year olds are nubile slim and pert?
And that having sex as an empty nester is nothing like the sex child free couples of the same age are having?
So no, I don't think child free couples have better, or more sex over the course of their marriages and lifetimes
They might not have pregnancies and births, or toddlers or wayward teens.. but there'll be plenty of other ups and downs: times of stress, variable health, mental health, other life upheavals, aging, changing....
And I think that any long term child free couple that imagine children as a permanent passion duller, are going to struggle to overcome whatever else life throws at their relationship and sex life.