Actually the original context is something like "the internet is not a big truck, it's a series of tubes" which makes it clear that he was referring to what was

Actually the original context is something like "the internet is not a big truck, it's a series of tubes" which makes it clear that he was referring to what was involved in sending data down a single connection. It would be absurd to infer that Stevens thought real-world truck haulage consisted of "one big truck" rather than a fleet.