You Aren’t Focusing on Your Subject Properly
Once you find a subject you want to use, you need to focus on it properly. Fortunately, your iPhone makes it really easy to focus on specific objects or people. Just tap on them wherever they appear on the screen, and your iPhone will try to make them clearer than the rest of the objects in the shot.
Of course, you can also do your part and move around so it’s easier to focus on the subject.