I don't agree with this at all. I spent a solid decade doing predominantly Windows development and I haven't felt the need to buy a book on any Microsoft topic

I don't agree with this at all. I spent a solid decade doing predominantly Windows development and I haven't felt the need to buy a book on any Microsoft topic since, like - "learn Visual Basic 5". While they probably had a good stretch of years from like after VS2008 until maybe after VS2015 where the documentation was clearly not a focus, I've never had any trouble learning first-and-foremost from the documentation and have often used MSDN as a good example of not needing to already understand the entire topic to benefit from first-party documentation on that topic.