All code is built on mountains of dependencies that by their nature will do more than what you are using them for. For example, part of cargo watch is to bring in a win32 API wrapper library (which is just autogenerated bindings for win32 calls). Of course that thing is going to be massive while watch is using only a sliver of it in the case it's built for windows.
The standard library for pretty much any language will have millions of lines of code, that's not scary even though your apps likely only use a fraction of what's offered.
And have you ever glanced at C++'s boost library? That thing is monstrously big yet most devs using it are going to really only grab a few of the extensions.
The alternative is the npm hellscape where you have a package for "isOdd" and a package for "is even" that can break the entire ecosystem if the owner is disgruntled because everything depends on them.
Having fewer larger dependencies maintained and relied on by multiple people is much more ideal and where rust mostly finds itself.