Well… this kind of breaks down when I think about how to make practical use of Distinguishable. Just from referencing the example from Identifiable I can see how we are mapping to some ideas that might not work well together:
If I would expect that a type that conforms to Distinguishable & Equatable and returns true for isIdentical should imply value equality between those two instances… that kind of breaks down when we consider that id should be stable even if other data fields change. Otherwise we would have a situation where two instances either return "the same" id for a false-positive when value equality returns false or return a different id and indicate this is an entirely new and different user. And neither of those outcomes really fit with what I was thinking for Distinguishable.