I've read this over and over again as something wasn't sitting right with me. I am open to discussing different ideas on the childfree choice and different terms and I am hugely grateful to you for raising this.
So I think my discomfort lies primarily here:
You say choosing not to have kids has lost it's stigma and it's become almost fashionable. You say this as if it is a fact, when actually it is your opinion. And perhaps it is a very realistic opinion based on your own world and perceptions. You have written a great book on the subject (I thoroughly enjoyed reading all the different accounts, so thank you), and you have clearly done your research. Which, perhaps means that you have attracted a flow of childfree people to your universe. For instance, your social media channels and real life network in general may well be fully accepting and embracing of the childfree. As such in your world there is no stigma and the term childfree is popular.
I feel this is similar to suggesting that the Queen thinks the world smells of paint, as everywhere she goes on official visits, is given a quick paint touch up for her arrival :-)
So, from where I stand, being childfree is still very stigmatised. I completely agree that this is VERY SLOWLY reducing thanks to all the books, podcasts, YouTube channels, articles, social media platforms and open conversations associated with being childfree and childless.
I think the term childfree is entirely fit for purpose and I will continue to use it with pride and confidence. I am proud to have survived some absolute hellish pressure to have kids from family and society. I am proud to be true to myself. I am proud that I am enough. I am proud to have the confidence now to feel no guilt.
I am proud to be childfree :-)
I would also like to think that maybe in the future, say in 10 years' time, I may read this article and agree with everything you have said - as it fits with my own lived experience. But until then, I think we have a fair way to go to really say that the stigma of the childfree has been eradicated.