This is a passage from a book published in 2017. Meanwhile, the HTML5 spec is quite ok with block elements such as divs descending from the anchor element (which is offered as the best example of an inline element here). HTML4.1 indeed had a problem with that, but HTML5 doesn’t.
The book is in its fourth edition, and this is such an outrageously problematic passage that I wonder whether it was copied wholesale from a previous edition.
