It's a completely different medium to be honest. Youtube is full of entertainment, but also there are thousands and thousands of great channels, from which you can learn amazing stuff. I remember that I used to watch videos explaining advanced maths when I was preparing for exams on YT. For example, I love Kurzgesagt channel and their approach for science. Books are something completely different, they are almost as old as civilization and it's difficult to compare them with YT. Both mediums can lead to some great knowledge, as well as - entertainment too.