DEI statements are just one factor in the hiring process for faculty. Generally they'll get scored by the hiring committee on some numeric scale (like everything else in the application). A low DEI score might not tank your application if you're in a field where everyone else has a low DEI score, or if you are absolutely outstanding in your field but have middling DEI because you're a white, male scientist from an affluent background who hasn't done much in that sense, you might still prevail. But it's a way of allowing the hiring committee to factor in diversity so that other things being equal (equal experience, equal credentials, equal letters of rec, teaching demo, etc) they can use diversity to distinguish candidates. The fuss about it is overblown.