That's not entirely true. If you want to write an entire standalone application that compiles into a binary and starts up a scheduler, then yes, you have to pi

That's not entirely true. If you want to write an entire standalone application that compiles into a binary and starts up a scheduler, then yes, you have to pick a scheduler runtime. If you're writing a library to be used by others you can very often expose only types which come from std::futures. The result will work with all of the runtimes.