20 years ago I'd buy books to learn Java, Linux, etc. These days if I want to learn something, I just start Googling.
I still think organized and structured information is helpful. We just need to devise a better way. I'm using Github for some things:
https://github.com/melling/ComputerLanguages
And for Swift and iOS where I want to go deeper, I'm creating my own Cookbook, and perhaps my own search engine: