Learning your Craft Matters
The sources that I'll refer to in a second and I agree with you: simply being exposed to writing is not enough to master the craft of writing. You also need clear concepts.
Learning Classic Style
Some of the answers here refer to 'style' guides. Most of these texts assume that style is superficial, in that changing words or their order can define a style.
This definition of style, as something superficial, is evaluated critically in Clear and Simple as the Truth by Francis-Noël Thomas and Mark Turner. They propose that style is fundamentally about the answer to a series of questions such as "Who is the speaker?" "Who is the audience?" "Is truth knowable?" "Is language able to convey truth?". Different answers to those questions define different styles, which they touch upon. But they do so mainly in contrast to Classic Style, which they help you develop by having clear thoughts regarding what it is(!) and exercises at the end of the book.
For what it's worth, I discovered this text via this Steven Pinker lecture. He also praises Classic Style for its benefits regarding clear communication.
Writing's Relationship to Knowledge Communities and Value
But even if you master Classic Style, that does not guarantee your writing will be valuable to your audience. Hence University of Chicago's writing program and the excelent Larry McEnerney. This lecture manages to cover epistemology, style, value, the craft of writing —all delivered in a way to make your writing valuable to a community.
If storytelling, learning about Story
Finally, if you're interested in storytelling in any form (movie scripts, novels, even storified advertisements), I'd recommend reading Robert McKee's Story. He lays out a view of how humans tend experience the world, how stories exploit that, and how they may subvert that experience tendency and story conventions. But apart from laying that evolutionary/experiential basis, he gives clear instruction as to how to develop dramatic stories, how to analyze other stories, how to analyze genres and subvert them, how to avoid clichés and create meaningful stories.
Every single one of these sources changed my life, both in the sense in which I think about many subjects, but also in the sense of changing my writing. They will give you clear concepts and tools that are sometimes broadly applicable and other times the perfect tool for a job that would've otherwise been hard if not impossible. They also give practical advice on how to apply their views of the world.