There are a number of benefits to using Backwards Design. First, it is more likely to lead to the outcomes we want for our students. We all want our students to be critical thinkers, problem solvers, and intellectually curious. Using a content first approach might lead to that result, but it more likely will not unless we have explicitly set goals for students to do things that demand critical thinking, problem solving, and intellectual curiosity, and then intentionally aligned everything in the course towards those outcomes.

Second, it's easier to be transparent with students about why things happen in your course the way they do. Ever struggle to answer a student who wants to know why they have to read that book or complete that assignment or work in that group? You'll always have an answer if you've used a Backwards Design approach to designing your course.

And finally but most importantly, designing your course with a backwards approach will actually make some tasks easier than beginning with a textbook or a set of planned activities. Once you know what you want students to be able to do, building assessments and planning activities becomes MUCH easier.

Here is a good article from Faculty Focus for more about how Backwards Design can be professionally beneficial to higher ed faculty.