[bpshaver]

But you can achieve #1 with typing.Protocol in type-annotated Python and traits in Rust. Fitting the "strict definition" sounds like nominal typing but you can opt in to explicit duck typing or structural typing while still being typed. (Someone correct me if I'm using these terms incorrectly.) In short you can still encode a lot of flexibility with types without just abandoning them alltogether.

And with #2, you can get that with static typing too... Let's say a method accepts an instance of an object `Foobar`. I can change the definition of `Foobar` ("change what shape [my] data is") without having to change type annotations everywhere.

I agree with you, I guess, that I find the steel man position unconvincing.