Although there are hundreds of textbooks on almost any topic, only a few of them are actually worth the time. The main reason for this horrible "signal-to-noise ratio" is described perfectly by C. Lanczos in his book The Variational Principles of Mechanics:
Many of the scientific treatises of today are formulated in a half-mystical language, as though to impress the reader with the uncomfortable feeling that he is in the permanent presence of a superman.
Most textbooks are written for the author, not for the reader. Almost all textbooks authors are mostly concerned with their reputation. Their main focus is on how the book makes them look. That's why most textbooks are unnecessarily complicated. If a textbook is hard to understand it makes the author appear like "superman". In addition, it is almost impossible to criticize some text that you don't fully understand. For the same reason, most authors restrict themselves to boring formulas and avoid any discussion about what they actually mean. Such interpretations could be easily criticized. However, these discussions of what things actually mean and not just dry formulas, are what helps students actually understand.
Equally problematic is that most students only know those textbooks that are usually recommended by professors: the "standard textbooks". They try reading them, understand little to nothing, give up and thus conclude that learning physics by reading is just not "their thing". The "standard textbooks" usually aren't the most student friendly. Instead, they usually resemble how professors think a topic should be taught.
Professors learned the topics they are teaching a long time ago and thus they already forgot what problems a student really faces. The "standard textbooks" are recommended because they share the expert attitude of most professors. However, experts usually aren't the best teachers. To quote C.S. Lewis:
"[The expert] sees the whole subject, by now, in a different light that he cannot conceive what is really troubling the pupil; he sees a dozen other difficulties which ought to be troubling him but aren't".
In addition, the fact that professors all around the world recommend the same textbooks is a problem on its own, because
“If you only read the books that everyone else is reading, you can only think what everyone else is thinking.” - from Norwegian Wood by H. Murakami
Most students never learn that they have to try dozens of textbooks until they find one that actually speaks a language they understand.
Luckily, there are a few authors who actually write to help their readers understand. Here in the Physics Travel Guide, we collect these textbooks because it is usually quite hard to find these "student friendly" books among all the"author friendly" books.
Often, when struggling with a book or paper, it's not you that's the problem, it's the author. Finding another source can quickly clear stuff up. - Michael Nielsen