That is too bad. I suspect this old man is a minority but I still read books. Online is great to "look stuff up" as a reference, and AI is a great reference source too, but reading the entire language specification cover to cover is an entirely different proposition and really can not be done "online". I am fine with an "online" book. If you only use it as a reference you only learn what you are looking for, and maybe a few things related and "nearby".
Topic:
Programming Languages
SubTopic:
Swift