In fact, in my experience K-12 biology textbooks are by far the most out of touch with the current state of their respective science, and it's for the simple reason that modern biology is always never out in the absence of evolutionary theory, but textbook makers don't want to embrace this due to fears of upsetting non-scientific parents.
The biological sciences have one of the strongest pedagological tools available in that they have a unified explanatory framework within which the entire field can be made sense of. No need to memorize non-connected facts without a context