I take it you didn’t read the whole thing, as the next example is NonEmptyList, which is a good compelling example. It’s also not hard to think of other examples from my own work: I can imagine a URL type that only exposes constructors to create well-formed URLs. Etc etc.

Really good examples will be rather domain-specific, so it’s perfectly understandable why Alexis would trust her readers to be able to imagine uses that suit their needs.