So true! I think the problem is particularly bad in high-school and first-year undergraduate textbooks, which are "padded" with useless extras, non-sense boxes,

So true! I think the problem is particularly bad in high-school and first-year undergraduate textbooks, which are "padded" with useless extras, non-sense boxes, and lots of blah blah to the point of being literally 5x thicker than they need to be. Let's face it, nobody is going to read a 1000+ page PHYS 101 textbook. Textbooks for graduate level courses are usually much better, as are textbooks outside the North American educational system, and best of all are old math textbooks from like 100+ years ago...