It used to be that you could buy a book and use it as a reference for years. That stopped being true sometime in the 1990s, as the half life of book value declined rapidly.

One persistent internet and Altavista became available it was just a matter of time, and now we're there. The whole move fast and break things culture won.

Like Chesterton's fence, you don't know what you're got until it's gone.

It depends on what kind of reference book you get.

A reference book on a particular language is going to have a pretty short useful lifetime, since any language of significant popularity will evolve relatively quickly.

In contrast, a reference book on general programming knowledge (e.g., design patterns) could very well last a lifetime.

You can still do it too, but you need to see through the fad and not go for the shiniest technology out there. I've been reading "The Design and Implementation of the 4.4BSD Operating System" because it's basically the best explanation about OpenBSD as it (and NetBSD) still follow the same general architecture.

Another book that's worth its weight is "The Linux Programming Interface" and "The TCP/IP Guide". Also you can probably buy "The Go Programming Language", "Programming Erlang", and "Programming Clojure" and still come ahead. As long as you choose to learn technologies that have thoughtful design, or has a standard (even a de-facto one), you're golden.