[reallyreason]

It could also be argued that putting a specific executor model into the standard library will make the problem worse because it will give library crates license to use it without considering alternatives because it is standard. At least today taking a dependency on a specific runtime is a well-known boondoggle .

[tracker1]

Not only that, but there kind of is a defacto standard (tokio), which is pretty much the default if you aren't in a specific, resource constrained use case.