I'm not sure whether such a curation needs (or should be) mixed up with the place where crates are "stored". Even if there was an "official recommendation list for packages" (made up by real humans or good AI algorithms, or both), crates.io could still stay the "data dump" it is and serve its purpose as such. From another thread:
However, we should also acknowledge that crates.io is more than just one Rust package repository. It is the default package registy on almost every installation of Rust. That gives it a special role (and responsibility?).
I guess it's a philosophical question whether crates.io (being in that role) should stay most "neutral" as in not judging about packages in any way, or be more trustworthy (perhaps a bit like an app store for consumers?) by providing more guidance. I don't really want to say that one or the other direction is best – just bringing up some thoughts.