That article claims that the standard starting prescription is 200mg spiro, but that's not accurate. It's 100mg, which in the article itself says that the effects from aren't nearly as dangerous as what it says. Also dr. Will Powers is kind of a hack and has in the past threatened Trans Fem Science, a free website where trans people can source academic information, with legal action for publishing criticism about his methodologies.
It's not the only source I've come across criticizing Spiro, and I believe the United States is the only country that pushes that stuff still despite my understanding better options—both estrogen alone and different anti-androgens with fewer side effects—are regularly proscribed in other countries.
Yes I agree CPA is proven to be more effective, but since its not available in the US spirits pretty much the only option. I agree its not the best and monotherapy is probably more viable, but there are very few options in the US especially with the affordability of spiro.
Again, there are things worth criticizing spiro for and its effectiveness - but that article puts out a decent amount of misinformation about the topic