Childfree to me is someone who has chosen not to have children
That can include infertile people
Infertility is a bit like a train journey. You can get off at the first station or you can go all the way through to the destination.
So you can decide that if you dont get pregnant "naturally" then you will give up
Or you can go to the thermometers and ovulation tracking station
Or the IVF station
You can change trains and go down the sperm donor or egg donor track
You might get off before you end up at surrogacy.
You might get off before you end up at adoption.
Because in the vast majority of cases most infertile people without children have actively made a decision to stop the journey. Whether thats deciding that 4 rounds of IVF is your limit, or deciding a sperm donor is not for you etc there tends to be an actual decision.
And that decision is a decision not to have children. Which is why many of us often tend to end up feeling more childfree than childless. Because often we also tend to embrace than decision as the years go on.
I desperately wanted children. But honestly if I got pregnant now I would have to strongly consider whether I even wanted a baby. because it turns out i actually like a childfree life and would be loath to give that up. So Im childfree and happy with that even if it did take a little while to get here.