Perhaps you're referring to things like regex and rand (each of which is itself multiple crates for the purpose of code organization), which are all first-party crates provided by the Rust organization itself, simply shipped and versioned separately from the standard library? If you trust the Rust organization enough to install and run the provided toolchain binaries on your machine, then you trust them enough to depend upon the dozens of crates that are provided under the umbrella of the Rust project.

Can you name 5 as an example?