This leads you to another book and so on. Too much hassle. That's not what you do in a library. It is very easy to move from one part of a document to another or from one website to another. You can go back and forwards easily.
Most sites have links to other parts of their site or links to sites by other authors.
This is an new style of reading. It is very easy once you get used to it. But you need to develop a bit of discipline if you are researching something because it can be very easy to get distracted and read something interesting but not relevant to your purpose. OR Copy it into your notebook. Complete these notes on the reading passage.