I'm lucky in the Al-Anon I've group I have found: it is definitely not religious - full of people like me who struggle with the concept of God, but the literature is very clear that it is God "as you understand him", and most of us substitute "the Universe" or "Goddess" or "Nature" which makes it a little easier to digest. Some even translate the words "higher power" to mean their own higher selves.
I do think AA would do better if they removed the references to God. It put me off for years.
I personally think the reason it has survived for so long has more to do with the traditions. In particular that there are no leaders, no egos, no governors, no money and anonymity is closely guarded.
I know of so many organisations that start out with spirituality at their core but fail because of their hierarchical structures.
Thank goodness there are alternatives to AA now. Smart recovery for one. And my personal favourite is the sweary Belle of Tired of Thinking About Drinking.
Great article, Marcus.
A🙏