It looks to me like the goals with typing.Protocol are for static type checking. Whereas this module is intended both for interfaces (much like ABCs) and implementation re-use (see Rust's "blanket implementations"). These Traits could definitely be used in type annotation, and maybe there's a way to use typing.Protocol with them to aid static type checking in Python. I haven't tried static type checking in Python yet, but it sounds promising!

> Whereas this module is intended both for interfaces (much like ABCs) and implementation re-use (see Rust's "blanket implementations")

That's the role typing.Protocol plays, as well. Protocols are like ABCs, but using structural typing.

Protocols can be used for runtime checks (isinstance), even for classes that are not explicitly annotated with them - that's the main point of structural subtyping.