Language features are a secondary consideration when compared to ecosystem and library availability as far as getting actual stuff done.
I never claimed those languages don't exist, but a language is a full package, and right now I'm not seeing even ascending languages as supporting trivial structural return types as an idiom. Granted, this is mostly a personal pet peeve given my observations and usage of code.
Me:
> Even for that there is no need for dynamic typing anymore. This problem has been solves with type parameters (aka generics) and type-classes.
This is obviously a general statement. I means "there can be a programming language where there is no need for dynamic typing to solve this kind of problem". And then I continue, that this problem has been solved. That means there is at least one such a language already existing which solves this problem with certain techniques.
Then you:
> Not true.
And once I offer you a concrete implementation as an example, you suddenly change the topic to "but... no mainstream language". And if I would present you a language that could be considered as mainstream, I'm sure you would find another restriction such as "but this language does not have enough... libraries".
Maybe you can give a minimal code example of what you mean and I'll show you how I would solve that in a statically typed way. :)