Most of us developers know can we can should abstract the network layer to support mocking, unit testing, and just to produce a more flexible design.
While lots of us know this, in practice it seems to get overly complicated and not always done well. A good design should simplify things, not complicate things. This is why I like this post focusing on using protocols to simplify network requests and improve testability. It even gets into decoding responses to give you a useful end-to-end flow.