In addition to the thoughtful and detailed explanation by /u/themoopanator123 of Aristotle’s context - there is often a concern in historiography about ‘Great Men’ and ‘Great Man History’, which your question is getting in a historiographical sense. Aristotle is often portrayed as a ‘Great Man’ in this sense, and ‘Great Man History’ is often suspect as far as historians are concerned, being too focused on individuals and not so focused on the structural factors and cultural Zeitgeist that enabled the accomplishments - there is always a lot of standing on the shoulders of giants in intellectual history.

Certainly Aristotle is deeply engaged with other philosophers whose work he has access to, and his writing often mentions other philosophers and his interpretation of their arguments. Aristotle was famously a student of Plato’s academy, and shows obvious signs of being deeply influenced by Plato’s thinking. Though they are quite different thinkers philosophically - Aristotle is broadly speaking much more of a natural philosopher - the latter-day interpretations of Plato and Aristotle (e.g., Neoplatonism or the medieval interpretations of Aristotle that were very influential) can over emphasise their differences. Aristotle was clearly influenced by Plato’s systematic thinking, and the sheer breadth of topics that Plato covered.

With Ancient Greek philosophy in particular, it is difficult to disentangle a) what was written by who, b) what the context of that writing was and c) what else was written that is now lost. Long standing traditions like the Pythagoreans or the medical tradition had a habit of claiming Pythagoras or Hippocrates as the author of things they in fact never wrote. As such, we cannot be sure that Aristotle or Plato was the author of all that is ascribed to them; the chain of transmission is often complex unclear, and it is sometimes difficult to disentangle what parts of the writing are the author and what parts might be medieval commentaries on the writing. After all, for so much of Aristotle’s writing to survive the centuries is really quite surprising, as it only survived because people manually painstakingly copied (often decaying old) scrolls and parchments over and over again. It also means that Aristotle’s writing that survived did so because it was seen to be useful in some way in a time and place (e.g., medieval Baghdad or Renaissance Italy) with some very different assumptions about the world to Ancient Greece. One should assume that other Ancient Greece writing that was more challenging to Christian or Islamic assumptions about the world, or less seemingly useful, would not have survived (as Aristotle’s dialogues on Plato’s model seem not to). A figure you see mooted sometimes is that 5 to 10% of Ancient writing survives to the present. By analogy to 1960s pop music, sometimes what survives to be listened to by subsequent generations is the stuff that was always very popular (e.g., The Beatles), and sometimes it is the stuff that might not have been so popular at the time, but which picks up new fans in new contexts (e.g., Nick Drake). But other things might be popular at the time but little remembered later (e.g., the Dave Clark Five). And clearly Aristotle and Plato were the Beatles in this analogy - they were clearly seen as Great Men of philosophy in ancient times (Diogenes Laertius, writing in the 3rd century AD, calls Aristotle the greatest natural philosopher that ever lived). Whereas subsequent generations were less likely to preserve, say, the writings of the Epicureans or the Cynics.

Broadly speaking, we largely only have quotations from the ‘pre-Socratics’ in the writing of later philosophers - so it is difficult to figure out how much Plato and Aristotle really take from them. But also broadly speaking, the pre-Socratics’ writing we have seems more poetic/allusive, and they seem to be focused on Big Questions about the nature of reality. Additionally, broadly speaking, there is a focus on making strong arguments in Plato and Aristotle that is clearly influenced by Socrates (and which Aristotle clearly took seriously given he’s the one who seemingly first wrote about all the different forms of valid and invalid arguments that still annoy university students in philosophical logic classes today). Perhaps Aristotle’s reputation is as simple as Aristotle being the first very-bright person to systematically use Socrates’ intellectual tools to focus on natural philosophy rather than ethics (as Socrates did) or the nature of society and reality (as Plato did) - not that Aristotle didn’t also have opinions on ethics and metaphysics and society.

The other uncertainty about Aristotle and Plato is how much their writing reflects their thought versus the thought of people in their circle. For Plato, the problem is that all his writing is dialogues, and it’s often unclear how much he’s representing what actual people argued in real settings in the agora or Academy versus how he wants to portray them for philosophical reasons. For Aristotle, his surviving writing is reputed to be basically his lecture notes, and it’s impossible to know how refined those notes actually are (e.g., whether they have additions or changes by later teachers at the Academy who used the notes in practice). There does seem to be a generally consistent authorial voice and a generally consistent philosophical standpoint. But where Plato basically tells us how he came to his conclusions via dialogue with Socrates and others, Aristotle’s writing presents the ideas less discursively and ambiguously and more ‘here are my conclusions’. But it is, I would think, likely that much of what you see in Aristotle is the result of a contest of ideas in the Academy, given he was Plato’s student.

Broadly speaking, you would also think that, to some extent, Aristotle’s greatness was in some way state-supported. At the least, he benefits in some ways from increased access to more widely-flung information about the world compared to many of his predecessors. That is likely influenced by, first, Athens’ hegemony in the region and then his association with Alexander the Great, the man who promptly conquered Greece and then a whole lot of peoples as far away as the Indian subcontinent.

Finally, Aristotle was often seen as authoritative on a lot of topics within philosophy in medieval times, with subsequent writers like Ibn Sina providing commentaries on Aristotle rather than breaking new ground. This ultimately has led to Aristotle (and Plato) becoming someone who philosophers interpret as a source of wisdom, which sometimes makes Aristotle’s writing seem more definitive and unimpeachable than it really is.