Big Companies Thrive Their Rankings So High While Smaller Voices Struggle Barely Catching An Eye

Riddle: I'm a digital oracle, a search engine supreme, Yet my results sometimes seem like a corporate dream. Type in a query, and behold what you find, But beware, my friend, for biases lurk behind. Big companies thrive, their rankings so high, While smaller voices struggle, barely catching an eye. Paid results intermingle with the organic fray, Untangling them? A PhD's work, they say. So, who am I? A gatekeeper of the web, Where algorithms reign, and transparency ebbs. My power immense, my reach vast and wide, But remember, dear user, there's more to see outside. What am I?