Socrates, Plato and Aristotle are often regarded at the greatest Greek philosophers. Yet rather than a culmination of Greek philosophy, they represent an aberration or even a counter-revolution.
Early Greek philosophers were mostly what we now call natural philosophers or scientists, attempting to explain observed events in terms of natural processes instead of the will of the Gods. They tended to be associated more with merchants and artisans than with landowners (the traditional ruling class). None of their writings survived, so what we know comes from commentaries by others. We know that the centers of philosophy were also centers of trade, like Miletus or Athens. Some were paid to teach. Some were presumably supported by their families. Zeno of Citium worked as a merchant until he was 42.
Socrates, Plato and Aristotle despised merchants, democracy, other philosophers and Athens in general. Their rhetorical style consisted largely of false dichotomies and bad analogies, and their conclusions are either dis-proven or too Zen to be meaningful. Aristotles journeys into natural philosophy invariably ended in disaster. For a man who wrote a book on logic, he had an unerring ability to reach the wrong conclusion.
The main contribution of Socrates, Plato and Aristotle to Western Civilization lies in making religious arguments without appearing to. The key is to distill divinity into abstract concepts like perfection. Perfection as a mental construct can be useful in simplifying observed reality. Plato regarded perfection as real and observation as flawed. Aristotle described the universe as a combination of matter and essence, where essence was perfect and complete but lacked substance.
Socrates' trial and execution for recruiting Athenians to join the Spartan army shows that he was as much a zealot as any modern cult leader. Plato regarded the universe as the product of a divine craftsman, and a model for rational souls to emulate. Aristotle's writings, some of which had survived in Irish monasteries and other recovered from Islamic libraries, played a major role in Scholasticism, which is a branch of Christian theology started in the 11th century.
Needless to say, their greatest admirers tend to be priests, starting with the Oracle of Delphi declaring Socrates to be the wisest Greek.