[kocyigityunus]

no, it's not. pdf has multiple rendering modes and your problem is the client you are using to view it.

the reason this book being ~20 mb with 750 pages is that %99 percent of the things inside is vectoral, including the variable font that I used. While trying to find the perfect page aspect ratio and the perfect variable font width, I tried it with many different screen sizes, operating systems, dpis etc and clearly tell you that you have another problem.