The Christian revolution around that time in Europe also put civilisation back there. See “The Darkening Age” by Catherine Nixey
A glance at Wikipedia ( https://en.wikipedia.org/wiki/The_Darkening_Age ) indicates that the book was not well received - not by Christians, but by academics.
The fact that the book won awards from NYT, Royal Society of Literature, BBC, and many other publications and is well-reviewed, yet Wikipedia only lists negative feedback in the Reception section indicates to me that there must be bias in the Wikipedia article. I don't see any other answer for why more than half of the article is just listing criticism that doesn't seem to be reflected across the broader industry.
Again I haven't read the book and don't really care about the subject matter either way, but the Wikipedia does not seem to hide its bias.