That's still the beautiful model you're referencing, not the reality of networking. If you saw what the actual network devices in the stack were doing, you would be... less impressed by the beauty, let's say. But they work, and they're fast. That has beauty of its own.

And I mean real network hardware through which the packets your received these words are, too, not just abstract theoretical "somebody's got something somewhere that does something weird". The model hasn't been accurate since before it was created.