Why do large providers avoid the legacy backbone path for internet traffic?

Question

In section 1.10.1 the book describes this 'legacy backbone' of internet traffic and how it still exists. Why might larger providers avoid this and use their own or another path? Obviously technology and hardware has evolved as well as availability zones. Could this possibly be so that they have more control over how their traffic is managed on the broader scope of the internet?

Answer 1

I have little knowledge of this but I would guess its for protection. By avoiding the backbone and using their own company backbone they avoid sniffing that could occur or congestion that might be present in the "legacy backbone"

That's at least what I surmise.