I believe that without.boats (or somebody of similar prominence) proposed that pollster (https://docs.rs/pollster/latest/pollster/) or a similar async executor be pulled into std.

I think it's a great idea. By blessing something that's not tokio you give a good incentive for library authors to test against more than one executor. And by being so far from fully featured pollster is never going to "win" so blessing it doesn't appoint a winner. And it gives an obvious solution for what people who don't want to use async in their code but do want to pull in an async library should do.

edit: it was without.boats in this post: https://without.boats/blog/why-async-rust/