I said this in a child comment - but to put it a different way - Imagine google didn't exist, how would you go about discovering content? When I first got on the internet there used to be directories, which was literally just a list of links sorted by topic. Although there was no "algorithm" I imagine (based on my own usage) that items listed closer to the top were more often clicked and thus grew faster than items lower on the list.

In fact, even before the internet, this phenomenon existed in the Yellow Pages which is why you have things like "aaa local plumbers" so they'd appear before their competitors.