I think the reason it's like this is because the C++ maintainers are super focused on noticing whenever there is a choice to be made, and being careful not to make it for you. Given the option between foisting situationally bad performance on you and foisting lots of syntax and interface complexity on you, they always choose the latter. Which I suppose makes sense: C++ niche is that it's the Big Gun you pull out when there's serious work to be done. So they figure you're already going to be dealing with massive complexity anyway, and you're going to be prepared for it. May as well let give you _all_ the access rather than fumbling at the 1 yard line by making some opinionated choice that is a non-starter for somebody, somewhere.

Most of that boilerplate will be hidden in the libraries which use it. Unless you are a library author I don’t know why you would care about the boilerplate-like elements from the standard— you will only use co_yield and co_await.

One reason could be that C++ tends to be used more in performance-critical contexts, and frequently the abstractions present in "every other language" can get in the way of performance.

On Windows that library is WinRT.