Rust and Cargo are, if not inseparable, at least tightly connected. Rust and Rust's stdlib are inseparable.
Cargo is modeled after NPM. It works more or less identically, and makes adding thousands of transient dependencies effortless, just like NPM.
Rust's stdlib is pretty anemic. It's significantly smaller than node's.
These are decisions made by the bodies governing Rust. It has predictable results.
ohh noo, the devs gave users a choice instead of forcing their hand..
Design decisions have predictable consequences. Large masses of people, who make up an ecosystem like the that of a programming language community, respond predictably to their environment. Each individual programmer has a choice, sure, but you can't just "individual responsibility" your way out of the predictable consequences of incentive structures.