Are you saying that using Google to answer a question is more exhausting than parsing a book? That makes zero sense
This is made worse by their size and scope. Spring Boot is a giant ecosystem, as is .NET, as is Azure, etc.
Also, search results tend to be a sea of data which might, or might not, contain some crucial bit of information that will help.
So, all too often, "using Google to answer a question" becomes a 2-hour or day-long research project to figure out how to solve some small, arcane problem like why the POST to some service doesn't have the Authorization header.
And when there's internal and external pressure to be productive, meet deadlines, and not feel incompetent, sometimes it gets frustrating and stressful and tiring.
My point is that we couldn't possibly do our jobs now without Google, but that we used to be able to do it just by knowing the stuff in a few books really well and knowing where—in the books or in e.g. manpages—to find what we didn't know. A small shelf of books is way better than Google, if you can be reasonably certain that the answers you need are in there.
Yes, this situation is far more exhausting.