Referrals (i.e. backlinks) are what Google uses to establish whether a domain and its content are trustworthy. The more trust it has in domain the better chance it stands of ranking pages in search results.
The problem is that established cycles of referrals, mentions, and increased page rankings tends to persist and build up over time.
If you look at a top 10 roundup of anything across any of your industry's big sites, they tend to mention the same things.
Well, one reason is that those are the top 10 in their niche. But another, perhaps less obvious, reason is that most people don't dig too deeply. Instead, they search on Google. And here's where it gets interesting, because...
Where does Google get its information?
From links given by earlier referrals.
The net effect being that people recycle older content because their research on Google shows up results that are linked from older pages. Those sites become more and more 'established' because as more people research them on Google and write about them, they receive more backlinks, better rankings, and more traffic - leading to more referrals.