Most importantly, a good foundation in music theory translates to an increased ability to overcome the learning curve when reading piano or other instruments scores. For lower grade music theory Grade 1 to 3, lessons focus on elements of music like stave, clefs, notes, time signature, key signature, rhythm and dynamics.
While opponents of music theory instruction may say that piano and other instruments proficiency may be achieved through many rounds of practice, I believe that if the fundamental elements like notes, rhythm and dynamics are wrongly identified, all the time and effort spent practicing will be in vain because the student will practice the wrong things!
