Light on facts and heavy on statements like, "all the latest studies show..." I agree that school is boring and that we don't teach big-picture or connectivity

Light on facts and heavy on statements like, "all the latest studies show..." I agree that school is boring and that we don't teach big-picture or connectivity enough. I believe this is because our teachers don't understand the domain they're teaching well enough. I've known a few teachers and their qualification courses to teach a given subject seem to be absolutely minimal. How can you teach how concepts are connected when your command of a subject goes no further than the current textbook?