I think it’s a mistake to think of a Stream as a single kind of datastructure. What exists is an Enumerable protocol, and then Enum functions to consume those Enumerables eagerly, and Stream functions to consume those Enumerables lazily. Absolutely anything that implements the Enumerable protocol is Enumerable. The standard library, mostly for I think easier pattern matching and IO.inspect purposes, has created some Stream named structs to represent certain constructs that have been built in a way that is amenable to streaming. That doesn’t mean that that fits every scenario however.
It’s also worth keeping in mind Elixir compatibility guarantees. At best you could deprecate the use of 2 arity functions as enumerables, but you can’t eliminate it without breaking people’s code that relies on this.
