I think maybe the right answer is to have a standardized, curated group of libraries pegged at some sort of LTS release that only backports security fixes. However, someone would need to pay for creating and maintaining this -- and then you wonder where the money would come from?
That or potentially fast tracking merging popular libraries into the standard library. Or at least concepts from popular libraries. Basically all the "most downloaded" crates on the Crates.io front page should be candidates for merging into the standard library.
https://crates.io/
Good ideas are pulled into the standard library.
https://crates.io/crates/once_cell
https://doc.rust-lang.org/std/cell/struct.OnceCell.html
Not everything should be eligible for this treatment. Certainly not an HTTP library or something without extremely widespread applicability.
Nearly all of my projects used once_cell, so it's good to see that pulled in. I wouldn't want to see anyhow, thiserror, anything opinionated, or anything domain specific in the std. That's a weight you have to bear forever.
Remember how long Python 2 -> 3 took, and look at the ancient and awful stuff in Python 3's standard library. Rust is not the right language for this.
someone tried doing this for rust, but the reaction was that it was vibe-coded/low quality.
https://github.com/rust-stdx/stdx
https://news.ycombinator.com/item?id=48571266
Note that there are baby versions of this that are uncontentious, for example
https://blessed.rs/crates
this is missing the LTS release. but it is a curated group of libraries that are relatively uncontentious to recommend.