Like many I have only read Naipaul’s nonfiction. His genius, as a literary intellectual, was to distill intuitions and observations that many of us have, but compress them into more economical and clear prose.
But, in my opinion, literary intellectuals’ genius lay not in uncovering new things, but unmasking what we already knew. Therefore Naipaul never presented me a startling insight that was totally novel, and much of his analysis I later rejected upon deeper study and thought. And yet if the question is the answer, then his prose definitely opened many mental doors.
Of course, others can speak to his fiction.