It depends on when it was. Back in 1999 it fit pretty well. Even if not perfect it still was a good teaching tool to explain "how it all works" on some level. Then you got to know the hairy details.
Nowadays "Internet" is mostly HTTP 2 for most people and then this model doesn't even remotely explain the structure of it.
Nowadays "Internet" is mostly HTTP 2 for most people and then this model doesn't even remotely explain the structure of it.