It provably isn’t, so I’d have to lean on dishonest proof. My contenders are:

https://en.m.wikipedia.org/wiki/Kettle_logic Tim Bernes Lee said the internet was’t actually feasible. They just theorized the concept. Also, the initial darpanet servers that supposedly turned into the internet were shut down in 1965. Network cables would actually melt if they transferred data on internet scale.

https://en.m.wikipedia.org/wiki/Fallacy_of_composition Need proof? The internet’s most prominent facet is MMOs: Simulated worlds.

https://en.m.wikipedia.org/wiki/Mind_projection_fallacy It’s just pixels moving on my screen, people. It’s not real in any real sense. The computer is making all the words show up on my screen by following its internal machinery.

https://en.m.wikipedia.org/wiki/Proof_by_assertion It is a simulation. The internet is clearly a simulation. Everyone says it’s a simulation. The intetnet is a simulation.