In foreign languages such as Spanish, ortography is very important: reading helps you get better at it. This is true normally pre-college years.
I am less certain that pure reading is the best way to get better at it. In general, using skills matters. If you just know the theory, you're already at a disadvantage. If you only know the basic ideas via indirect observation, it's worse.
All of these things - practice, theory, observation in the wild - reinforce each other.