Are you asking about the advantage of online search as opposed to looking things up in actual physical books? If so, it's like the advantage of telephoning someone who lives 10 miles away over walking to talk to them.
As someone who had to look up lots of stuff in the days before the internet, I tell you that it was no fun at all. For little things, you had to have a set of encyclopedias. That cost a lot of money, quickly went out of date, and gave you access to only one perspective.
Then when it came to research papers, things were even worse. You would have to find out where the information was located and go there and get it. For example, I remember having to drive 50 miles to the state archives to find some information that I could now get standing here in my kitchen.